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    <link:label xlink:label="us-gaap_DerivativeGainLossOnDerivativeNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DerivativeGainLossOnDerivativeNet</link:label>
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    <link:label xlink:label="poai_NoteToFinancialStatementDetailsTextual-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note To Financial Statement Details Textual</link:label>
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    <link:loc xlink:href="poai-20211231.xsd#poai_statement-statement-significant-accounting-policies-policies" xlink:label="poai_statement-statement-significant-accounting-policies-policies" xlink:type="locator"/>
    <link:label xlink:label="poai_statement-statement-significant-accounting-policies-policies-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Significant Accounting Policies</link:label>
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    <link:loc xlink:href="poai-20211231.xsd#poai_statement-statement-note-1-summary-of-significant-accounting-policies-tables" xlink:label="poai_statement-statement-note-1-summary-of-significant-accounting-policies-tables" xlink:type="locator"/>
    <link:label xlink:label="poai_statement-statement-note-1-summary-of-significant-accounting-policies-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 1 - Summary of Significant Accounting Policies</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate</link:label>
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    <link:loc xlink:href="poai-20211231.xsd#poai_statement-statement-note-2-zpredicta-acquisition-tables" xlink:label="poai_statement-statement-note-2-zpredicta-acquisition-tables" xlink:type="locator"/>
    <link:label xlink:label="poai_statement-statement-note-2-zpredicta-acquisition-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 2 - zPredicta Acquisition</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Risk-free interest rate</link:label>
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    <link:loc xlink:href="poai-20211231.xsd#poai_statement-statement-note-3-inventories-tables" xlink:label="poai_statement-statement-note-3-inventories-tables" xlink:type="locator"/>
    <link:label xlink:label="poai_statement-statement-note-3-inventories-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 3 - Inventories</link:label>
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    <link:loc xlink:href="poai-20211231.xsd#poai_statement-statement-note-6-notes-payable-tables" xlink:label="poai_statement-statement-note-6-notes-payable-tables" xlink:type="locator"/>
    <link:label xlink:label="poai_statement-statement-note-6-notes-payable-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 6 - Notes Payable</link:label>
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    <link:loc xlink:href="poai-20211231.xsd#poai_statement-statement-note-7-derivatives-tables" xlink:label="poai_statement-statement-note-7-derivatives-tables" xlink:type="locator"/>
    <link:label xlink:label="poai_statement-statement-note-7-derivatives-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 7 - Derivatives</link:label>
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    <link:loc xlink:href="poai-20211231.xsd#poai_statement-statement-note-8-loss-per-share-tables" xlink:label="poai_statement-statement-note-8-loss-per-share-tables" xlink:type="locator"/>
    <link:label xlink:label="poai_statement-statement-note-8-loss-per-share-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 8 - Loss Per Share</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets</link:label>
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    <link:loc xlink:href="poai-20211231.xsd#poai_statement-statement-note-9-income-taxes-tables" xlink:label="poai_statement-statement-note-9-income-taxes-tables" xlink:type="locator"/>
    <link:label xlink:label="poai_statement-statement-note-9-income-taxes-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 9 - Income Taxes</link:label>
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    <link:label xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables</link:label>
    <link:label xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accounts receivable</link:label>
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    <link:loc xlink:href="poai-20211231.xsd#poai_statement-statement-note-10-goodwill-and-intangibles-tables" xlink:label="poai_statement-statement-note-10-goodwill-and-intangibles-tables" xlink:type="locator"/>
    <link:label xlink:label="poai_statement-statement-note-10-goodwill-and-intangibles-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 10 - Goodwill and Intangibles</link:label>
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    <link:loc xlink:href="poai-20211231.xsd#poai_statement-statement-note-11-leases-tables" xlink:label="poai_statement-statement-note-11-leases-tables" xlink:type="locator"/>
    <link:label xlink:label="poai_statement-statement-note-11-leases-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 11 - Leases</link:label>
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    <link:loc xlink:href="poai-20211231.xsd#poai_statement-statement-note-12-property-plant-and-equipment-tables" xlink:label="poai_statement-statement-note-12-property-plant-and-equipment-tables" xlink:type="locator"/>
    <link:label xlink:label="poai_statement-statement-note-12-property-plant-and-equipment-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 12 - Property, Plant and Equipment</link:label>
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    <link:label xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents</link:label>
    <link:label xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cash</link:label>
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    <link:loc xlink:href="poai-20211231.xsd#poai_statement-statement-note-13-segments-tables" xlink:label="poai_statement-statement-note-13-segments-tables" xlink:type="locator"/>
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    <link:label xlink:label="us-gaap_LiabilitiesCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LiabilitiesCurrent</link:label>
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    <link:label xlink:label="poai_statement-statement-note-2-zpredicta-acquisition-pro-form-information-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 2 - zPredicta Acquisition - Pro Form Information (Details)</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Expected life (years) (Year)</link:label>
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    <link:label xlink:label="us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable</link:label>
    <link:label xlink:label="us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Business Combination, Consideration Transferred, Equity Interests Issued and Issuable</link:label>
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    <link:label xlink:label="poai_statement-statement-note-4-stockholders-equity-stock-options-and-warrants-stock-offerings-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 4 - Stockholders' Equity, Stock Options and Warrants - Stock Offerings (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_statement-statement-note-4-stockholders-equity-stock-options-and-warrants-stock-offerings-details" xlink:to="poai_statement-statement-note-4-stockholders-equity-stock-options-and-warrants-stock-offerings-details-label" xlink:type="arc"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_statement-statement-note-4-stockholders-equity-stock-options-and-warrants-summary-of-transactions-for-stock-options-and-warrants-details" xlink:to="poai_statement-statement-note-4-stockholders-equity-stock-options-and-warrants-summary-of-transactions-for-stock-options-and-warrants-details-label" xlink:type="arc"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_statement-statement-note-4-stockholders-equity-stock-options-and-warrants-summary-of-status-of-options-and-warrants-outstanding-details" xlink:to="poai_statement-statement-note-4-stockholders-equity-stock-options-and-warrants-summary-of-status-of-options-and-warrants-outstanding-details-label" xlink:type="arc"/>
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    <link:label xlink:label="poai_statement-statement-note-4-stockholders-equity-stock-options-and-warrants-schedule-of-listing-of-stock-options-and-warrants-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 4 - Stockholders' Equity, Stock Options and Warrants - Schedule of Listing of Stock Options and Warrants (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_statement-statement-note-4-stockholders-equity-stock-options-and-warrants-schedule-of-listing-of-stock-options-and-warrants-details" xlink:to="poai_statement-statement-note-4-stockholders-equity-stock-options-and-warrants-schedule-of-listing-of-stock-options-and-warrants-details-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_LaboratoryEquipmentMember" xlink:label="poai_LaboratoryEquipmentMember" xlink:type="locator"/>
    <link:label xlink:label="poai_LaboratoryEquipmentMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Laboratory Equipment [Member]</link:label>
    <link:label xlink:label="poai_LaboratoryEquipmentMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information pertaining to laboratory equipment.</link:label>
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    <link:label xlink:label="poai_statement-statement-note-6-notes-payable-notes-payable-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 6 - Notes Payable - Notes Payable (Details)</link:label>
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    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Average Exercise Price Issued (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_statement-statement-note-11-leases-lease-information-details" xlink:label="poai_statement-statement-note-11-leases-lease-information-details" xlink:type="locator"/>
    <link:label xlink:label="poai_statement-statement-note-11-leases-lease-information-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 11 - Leases - Lease Information (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_statement-statement-note-11-leases-lease-information-details" xlink:to="poai_statement-statement-note-11-leases-lease-information-details-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLiabilitiesCurrent" xlink:label="us-gaap_DerivativeLiabilitiesCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DerivativeLiabilitiesCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative Liability</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeLiabilitiesCurrent" xlink:to="us-gaap_DerivativeLiabilitiesCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PrefundedWarrantsMember" xlink:label="poai_PrefundedWarrantsMember" xlink:type="locator"/>
    <link:label xlink:label="poai_PrefundedWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Prefunded Warrants [Member]</link:label>
    <link:label xlink:label="poai_PrefundedWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to prefunded warrants.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PrefundedWarrantsMember" xlink:to="poai_PrefundedWarrantsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_statement-statement-note-11-leases-rent-obligation-details" xlink:label="poai_statement-statement-note-11-leases-rent-obligation-details" xlink:type="locator"/>
    <link:label xlink:label="poai_statement-statement-note-11-leases-rent-obligation-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 11 - Leases - Rent Obligation (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_statement-statement-note-11-leases-rent-obligation-details" xlink:to="poai_statement-statement-note-11-leases-rent-obligation-details-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Average Exercise Price Forfeited (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_statement-statement-note-12-property-plant-and-equipment-schedule-of-property-plant-and-equipment-details" xlink:label="poai_statement-statement-note-12-property-plant-and-equipment-schedule-of-property-plant-and-equipment-details" xlink:type="locator"/>
    <link:label xlink:label="poai_statement-statement-note-12-property-plant-and-equipment-schedule-of-property-plant-and-equipment-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 12 - Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_statement-statement-note-12-property-plant-and-equipment-schedule-of-property-plant-and-equipment-details" xlink:to="poai_statement-statement-note-12-property-plant-and-equipment-schedule-of-property-plant-and-equipment-details-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue-label" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Average Exercise Price Outstanding (in dollars per share)</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue-label" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Average Exercise Price Outstanding (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_statement-statement-note-13-segments-segments-details" xlink:label="poai_statement-statement-note-13-segments-segments-details" xlink:type="locator"/>
    <link:label xlink:label="poai_statement-statement-note-13-segments-segments-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 13 - Segments - Segments (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_statement-statement-note-13-segments-segments-details" xlink:to="poai_statement-statement-note-13-segments-segments-details-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_NotesToFinancialStatements" xlink:label="poai_NotesToFinancialStatements" xlink:type="locator"/>
    <link:label xlink:label="poai_NotesToFinancialStatements-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Notes To Financial Statements</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_NotesToFinancialStatements" xlink:to="poai_NotesToFinancialStatements-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_NotesToFinancialStatementsAbstract" xlink:label="poai_NotesToFinancialStatementsAbstract" xlink:type="locator"/>
    <link:label xlink:label="poai_NotesToFinancialStatementsAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Notes To Financial Statements [Abstract]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_NotesToFinancialStatementsAbstract" xlink:to="poai_NotesToFinancialStatementsAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetImpairment" xlink:label="us-gaap_GoodwillAndIntangibleAssetImpairment" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_GoodwillAndIntangibleAssetImpairment-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_GoodwillAndIntangibleAssetImpairment</link:label>
    <link:label xlink:label="us-gaap_GoodwillAndIntangibleAssetImpairment-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Impairment expense</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillAndIntangibleAssetImpairment" xlink:to="us-gaap_GoodwillAndIntangibleAssetImpairment-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1</link:label>
    <link:label xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term (Year)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:label="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss</link:label>
    <link:label xlink:label="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Net loss attributable to common shareholders</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:to="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NotesPayableCurrent" xlink:label="us-gaap_NotesPayableCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NotesPayableCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Notes Payable &#8211; Net of Discounts of $0 and $244,830</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesPayableCurrent" xlink:to="us-gaap_NotesPayableCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionProFormaInformationTextBlock" xlink:label="us-gaap_BusinessAcquisitionProFormaInformationTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_BusinessAcquisitionProFormaInformationTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Business Acquisition, Pro Forma Information [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionProFormaInformationTextBlock" xlink:to="us-gaap_BusinessAcquisitionProFormaInformationTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:label="us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_BusinessAcquisitionsProFormaRevenue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_BusinessAcquisitionsProFormaRevenue</link:label>
    <link:label xlink:label="us-gaap_BusinessAcquisitionsProFormaRevenue-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Revenue</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:to="us-gaap_BusinessAcquisitionsProFormaRevenue-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Weighted average remaining life, options (Year)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SeriesDConvertiblePreferredStockMember" xlink:label="poai_SeriesDConvertiblePreferredStockMember" xlink:type="locator"/>
    <link:label xlink:label="poai_SeriesDConvertiblePreferredStockMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Series D Convertible Preferred Stock [Member]</link:label>
    <link:label xlink:label="poai_SeriesDConvertiblePreferredStockMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the information pertaining to the Series D Convertible Preferred Stock.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SeriesDConvertiblePreferredStockMember" xlink:to="poai_SeriesDConvertiblePreferredStockMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Financial Instruments [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillImpairedAccumulatedImpairmentLoss" xlink:label="us-gaap_GoodwillImpairedAccumulatedImpairmentLoss" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_GoodwillImpairedAccumulatedImpairmentLoss-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_GoodwillImpairedAccumulatedImpairmentLoss</link:label>
    <link:label xlink:label="us-gaap_GoodwillImpairedAccumulatedImpairmentLoss-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Goodwill, Impaired, Accumulated Impairment Loss</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillImpairedAccumulatedImpairmentLoss" xlink:to="us-gaap_GoodwillImpairedAccumulatedImpairmentLoss-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:type="locator"/>
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    <link:label xlink:label="us-gaap_TradeNamesMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Trade Names [Member]</link:label>
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    <link:label xlink:label="us-gaap_StockIssued1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares issued pursuant to convertible debt</link:label>
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    <link:label xlink:label="us-gaap_OtherIntangibleAssetsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Intangible Assets [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherIntangibleAssetsMember" xlink:to="us-gaap_OtherIntangibleAssetsMember-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_PaymentsToAcquireIntangibleAssets-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_PaymentsToAcquireIntangibleAssets</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireIntangibleAssets" xlink:to="us-gaap_PaymentsToAcquireIntangibleAssets-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Indefinite-lived Intangible Assets [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:type="locator"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_PaymentsToAcquirePropertyPlantAndEquipment</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Non-cash transactions</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="us-gaap_NoncashInvestingAndFinancingItemsAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod</link:label>
    <link:label xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodValueExchangeAgreementAccruedInterest" xlink:label="poai_StockIssuedDuringPeriodValueExchangeAgreementAccruedInterest" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodValueExchangeAgreementAccruedInterest-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Shares issued pursuant to former CEO per agreement related to accrued interest</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodValueExchangeAgreementAccruedInterest-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_StockIssuedDuringPeriodValueExchangeAgreementAccruedInterest</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodValueExchangeAgreementAccruedInterest-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The value of shares issued during the period for exchange agreements accrued interest.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodValueExchangeAgreementAccruedInterest" xlink:to="poai_StockIssuedDuringPeriodValueExchangeAgreementAccruedInterest-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">LIABILITIES AND STOCKHOLDERS' EQUITY</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquityAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DevelopedTechnologyRightsMember" xlink:label="us-gaap_DevelopedTechnologyRightsMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DevelopedTechnologyRightsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Developed Technology Rights [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DevelopedTechnologyRightsMember" xlink:to="us-gaap_DevelopedTechnologyRightsMember-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_Assets-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Assets</link:label>
    <link:label xlink:label="us-gaap_Assets-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_Assets</link:label>
    <link:label xlink:label="us-gaap_Assets-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total Assets</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SupplementalCashFlowInformationAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash paid during the period for:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="us-gaap_SupplementalCashFlowInformationAbstract-label" xlink:type="arc"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock" xlink:to="us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="us-gaap_PlanNameAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PlanNameAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Plan Name [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="us-gaap_PlanNameDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PlanNameDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Plan Name [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameDomain" xlink:to="us-gaap_PlanNameDomain-label" xlink:type="arc"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_OperatingLeaseExpense-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_OperatingLeaseExpense</link:label>
    <link:label xlink:label="us-gaap_OperatingLeaseExpense-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating Lease, Expense</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseExpense" xlink:to="us-gaap_OperatingLeaseExpense-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:type="locator"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net loss attributable to common shareholders per common share: basic and diluted calculation</link:label>
    <link:label xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net loss attributable to common shareholders</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="us-gaap_CustomerRelationshipsMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CustomerRelationshipsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Customer Relationships [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CustomerRelationshipsMember" xlink:to="us-gaap_CustomerRelationshipsMember-label" xlink:type="arc"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:type="locator"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain-label" xlink:type="arc"/>
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    <link:label xlink:label="poai_PreferredStockBeneficialConversionFeature-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Preferred Stock, Beneficial Conversion Feature</link:label>
    <link:label xlink:label="poai_PreferredStockBeneficialConversionFeature-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amount of intrinsic value at the time of issuance.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PreferredStockBeneficialConversionFeature" xlink:to="poai_PreferredStockBeneficialConversionFeature-label" xlink:type="arc"/>
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    <link:label xlink:label="poai_WarrantsIssuedPursuantTo2020ConvertibleDebtMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants Issued Pursuant to 2020 Convertible Debt [Member]</link:label>
    <link:label xlink:label="poai_WarrantsIssuedPursuantTo2020ConvertibleDebtMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents warrants which were issued pursuant to 2020 convertible debt.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantsIssuedPursuantTo2020ConvertibleDebtMember" xlink:to="poai_WarrantsIssuedPursuantTo2020ConvertibleDebtMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis" xlink:label="us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Error Correction, Type [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis" xlink:to="us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdjustmentsForErrorCorrectionDomain" xlink:label="us-gaap_AdjustmentsForErrorCorrectionDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AdjustmentsForErrorCorrectionDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Error Correction, Type [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsForErrorCorrectionDomain" xlink:to="us-gaap_AdjustmentsForErrorCorrectionDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityDividendsAdjustment" xlink:label="us-gaap_TemporaryEquityDividendsAdjustment" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_TemporaryEquityDividendsAdjustment-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deemed dividend</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TemporaryEquityDividendsAdjustment" xlink:to="us-gaap_TemporaryEquityDividendsAdjustment-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Award Type [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodValueInducementToPromissoryNoteExtension" xlink:label="poai_StockIssuedDuringPeriodValueInducementToPromissoryNoteExtension" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodValueInducementToPromissoryNoteExtension-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Inducement shares issued pursuant to promissory note extension</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodValueInducementToPromissoryNoteExtension-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Value of stock issued for the inducement to promissory note extension.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodValueInducementToPromissoryNoteExtension" xlink:to="poai_StockIssuedDuringPeriodValueInducementToPromissoryNoteExtension-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardDateAxis" xlink:label="us-gaap_AwardDateAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AwardDateAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Award Date [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AwardDateAxis" xlink:to="us-gaap_AwardDateAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardDateDomain" xlink:label="us-gaap_AwardDateDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AwardDateDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Award Date [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AwardDateDomain" xlink:to="us-gaap_AwardDateDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AwardTypeAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Award Type [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_AwardTypeAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NetIncomeLoss-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net loss</link:label>
    <link:label xlink:label="us-gaap_NetIncomeLoss-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Net loss</link:label>
    <link:label xlink:label="us-gaap_NetIncomeLoss-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net loss</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_IssuanceOfSharesAndPrefundedWarrantsPursuantToPrivatePlacementValue" xlink:label="poai_IssuanceOfSharesAndPrefundedWarrantsPursuantToPrivatePlacementValue" xlink:type="locator"/>
    <link:label xlink:label="poai_IssuanceOfSharesAndPrefundedWarrantsPursuantToPrivatePlacementValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Issuance of shares and prefunded warrants pursuant to March 2020 private placement</link:label>
    <link:label xlink:label="poai_IssuanceOfSharesAndPrefundedWarrantsPursuantToPrivatePlacementValue-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The value of shares and prefunded warrants issued pursuant to private placement.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_IssuanceOfSharesAndPrefundedWarrantsPursuantToPrivatePlacementValue" xlink:to="poai_IssuanceOfSharesAndPrefundedWarrantsPursuantToPrivatePlacementValue-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization</link:label>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Accumulated Amortization</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Carrying Amount</link:label>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsNet" xlink:to="us-gaap_FiniteLivedIntangibleAssetsNet-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Total, Net Carrying Amount</link:label>
    <link:label xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Intangibles, net</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodSharesInducementToPromissoryNoteExtension" xlink:label="poai_StockIssuedDuringPeriodSharesInducementToPromissoryNoteExtension" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesInducementToPromissoryNoteExtension-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Inducement shares issued pursuant to promissory note extension (in shares)</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesInducementToPromissoryNoteExtension-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The number of stock issued for the inducement to promissory note extension.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodSharesInducementToPromissoryNoteExtension" xlink:to="poai_StockIssuedDuringPeriodSharesInducementToPromissoryNoteExtension-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodSharesExchangeAgreement" xlink:label="poai_StockIssuedDuringPeriodSharesExchangeAgreement" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesExchangeAgreement-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Shares issued pursuant to CEO note conversion and accrued interest and exchange agreement (in shares)</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesExchangeAgreement-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_StockIssuedDuringPeriodSharesExchangeAgreement</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesExchangeAgreement-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The number of shares issued during the period for exchange agreements.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodSharesExchangeAgreement" xlink:to="poai_StockIssuedDuringPeriodSharesExchangeAgreement-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodSharesInducementToPrivatePlacement" xlink:label="poai_StockIssuedDuringPeriodSharesInducementToPrivatePlacement" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesInducementToPrivatePlacement-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Issuance of shares and prefunded warrants pursuant to March 2020 private placement (in shares)</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesInducementToPrivatePlacement-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The number of shares issued for the inducement to private placement.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodSharesInducementToPrivatePlacement" xlink:to="poai_StockIssuedDuringPeriodSharesInducementToPrivatePlacement-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Gross Carrying Costs</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsGross" xlink:to="us-gaap_FiniteLivedIntangibleAssetsGross-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConvertibleDebtSecuritiesMember" xlink:label="us-gaap_ConvertibleDebtSecuritiesMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ConvertibleDebtSecuritiesMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Convertible Debt Securities [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConvertibleDebtSecuritiesMember" xlink:to="us-gaap_ConvertibleDebtSecuritiesMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="us-gaap_EmployeeStockOptionMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_EmployeeStockOptionMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Payment Arrangement, Option [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeStockOptionMember" xlink:to="us-gaap_EmployeeStockOptionMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WarrantMember" xlink:label="us-gaap_WarrantMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_WarrantMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrant [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WarrantMember" xlink:to="us-gaap_WarrantMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:to="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Antidilutive Securities [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Antidilutive Securities, Name [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_AntidilutiveSecuritiesNameDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillAcquiredDuringPeriod" xlink:label="us-gaap_GoodwillAcquiredDuringPeriod" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_GoodwillAcquiredDuringPeriod-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_GoodwillAcquiredDuringPeriod</link:label>
    <link:label xlink:label="us-gaap_GoodwillAcquiredDuringPeriod-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Goodwill, Acquired During Period</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillAcquiredDuringPeriod" xlink:to="us-gaap_GoodwillAcquiredDuringPeriod-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Tradename</link:label>
    <link:label xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_GoodwillIncreaseInDiscountRateOf05PercentReductionInFairValue" xlink:label="poai_GoodwillIncreaseInDiscountRateOf05PercentReductionInFairValue" xlink:type="locator"/>
    <link:label xlink:label="poai_GoodwillIncreaseInDiscountRateOf05PercentReductionInFairValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_GoodwillIncreaseInDiscountRateOf05PercentReductionInFairValue</link:label>
    <link:label xlink:label="poai_GoodwillIncreaseInDiscountRateOf05PercentReductionInFairValue-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Goodwill, Increase in Discount Rate of 0.5 Percent, Reduction in Fair Value</link:label>
    <link:label xlink:label="poai_GoodwillIncreaseInDiscountRateOf05PercentReductionInFairValue-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The amount of reduction in fair value that would occur if the discount rate increased by 0.5%.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_GoodwillIncreaseInDiscountRateOf05PercentReductionInFairValue" xlink:to="poai_GoodwillIncreaseInDiscountRateOf05PercentReductionInFairValue-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodSharesWarrantExercises" xlink:label="poai_StockIssuedDuringPeriodSharesWarrantExercises" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesWarrantExercises-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_StockIssuedDuringPeriodSharesWarrantExercises</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesWarrantExercises-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Stock Issued During Period, Shares, Warrant Exercises (in shares)</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesWarrantExercises-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The number of shares issued during the period for exercise of warrants.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodSharesWarrantExercises" xlink:to="poai_StockIssuedDuringPeriodSharesWarrantExercises-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablesTextBlock" xlink:label="us-gaap_FinancingReceivablesTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FinancingReceivablesTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Financing Receivables [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinancingReceivablesTextBlock" xlink:to="us-gaap_FinancingReceivablesTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationDisclosureTextBlock" xlink:label="us-gaap_BusinessCombinationDisclosureTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_BusinessCombinationDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Business Combination Disclosure [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationDisclosureTextBlock" xlink:to="us-gaap_BusinessCombinationDisclosureTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Less: Accumulated depreciation</link:label>
    <link:label xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:to="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fixed Assets, net</link:label>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentNet-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total fixed assets, net</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentNet" xlink:to="us-gaap_PropertyPlantAndEquipmentNet-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Goodwill" xlink:label="us-gaap_Goodwill" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_Goodwill-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Goodwill</link:label>
    <link:label xlink:label="us-gaap_Goodwill-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Goodwill, Ending Balance</link:label>
    <link:label xlink:label="us-gaap_Goodwill-label" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Goodwill</link:label>
    <link:label xlink:label="us-gaap_Goodwill-label" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Goodwill</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Goodwill" xlink:to="us-gaap_Goodwill-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_GoodwillDecreaseInGrowthRateOf05PercentReductionInFairValue" xlink:label="poai_GoodwillDecreaseInGrowthRateOf05PercentReductionInFairValue" xlink:type="locator"/>
    <link:label xlink:label="poai_GoodwillDecreaseInGrowthRateOf05PercentReductionInFairValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_GoodwillDecreaseInGrowthRateOf05PercentReductionInFairValue</link:label>
    <link:label xlink:label="poai_GoodwillDecreaseInGrowthRateOf05PercentReductionInFairValue-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Goodwill, Decrease in Growth Rate of 0.5 Percent, Reduction in Fair Value</link:label>
    <link:label xlink:label="poai_GoodwillDecreaseInGrowthRateOf05PercentReductionInFairValue-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The amount of reduction in fair value if the growth rate decreased by 0.5%.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_GoodwillDecreaseInGrowthRateOf05PercentReductionInFairValue" xlink:to="poai_GoodwillDecreaseInGrowthRateOf05PercentReductionInFairValue-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_DrSchwartzMember" xlink:label="poai_DrSchwartzMember" xlink:type="locator"/>
    <link:label xlink:label="poai_DrSchwartzMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Dr. Schwartz [Member]</link:label>
    <link:label xlink:label="poai_DrSchwartzMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents Dr. Schwartz.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_DrSchwartzMember" xlink:to="poai_DrSchwartzMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_WarrantsIssuedWithPromissoryNoteThreeMember" xlink:label="poai_WarrantsIssuedWithPromissoryNoteThreeMember" xlink:type="locator"/>
    <link:label xlink:label="poai_WarrantsIssuedWithPromissoryNoteThreeMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants Issued With Promissory Note, Three [Member]</link:label>
    <link:label xlink:label="poai_WarrantsIssuedWithPromissoryNoteThreeMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the warrants issued with the third tranche of promissory note.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantsIssuedWithPromissoryNoteThreeMember" xlink:to="poai_WarrantsIssuedWithPromissoryNoteThreeMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PromissoryNote2020Member" xlink:label="poai_PromissoryNote2020Member" xlink:type="locator"/>
    <link:label xlink:label="poai_PromissoryNote2020Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Promissory Note 2020 [Member]</link:label>
    <link:label xlink:label="poai_PromissoryNote2020Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents promissory note 2020.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PromissoryNote2020Member" xlink:to="poai_PromissoryNote2020Member-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="us-gaap_PropertyPlantAndEquipmentGross" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentGross-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Property, Plant, and Equipment Gross</link:label>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentGross-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_PropertyPlantAndEquipmentGross</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentGross" xlink:to="us-gaap_PropertyPlantAndEquipmentGross-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_TradeNames1Member" xlink:label="poai_TradeNames1Member" xlink:type="locator"/>
    <link:label xlink:label="poai_TradeNames1Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Trade Names 1 [Member]</link:label>
    <link:label xlink:label="poai_TradeNames1Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Rights acquired through registration of a business name to gain or protect exclusive use thereof.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_TradeNames1Member" xlink:to="poai_TradeNames1Member-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SecondPromissoryNoteMember" xlink:label="poai_SecondPromissoryNoteMember" xlink:type="locator"/>
    <link:label xlink:label="poai_SecondPromissoryNoteMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Second Promissory Note [Member]</link:label>
    <link:label xlink:label="poai_SecondPromissoryNoteMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the second promissory note.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SecondPromissoryNoteMember" xlink:to="poai_SecondPromissoryNoteMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedAgreementNotToBeTransferredOrSoldForSixMonths" xlink:label="poai_StockIssuedAgreementNotToBeTransferredOrSoldForSixMonths" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedAgreementNotToBeTransferredOrSoldForSixMonths-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_StockIssuedAgreementNotToBeTransferredOrSoldForSixMonths</link:label>
    <link:label xlink:label="poai_StockIssuedAgreementNotToBeTransferredOrSoldForSixMonths-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Stock Issued, Agreement, Not to be Transferred or Sold for Six Months (in shares)</link:label>
    <link:label xlink:label="poai_StockIssuedAgreementNotToBeTransferredOrSoldForSixMonths-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The number of shares issued under agreement that are not to be transferred or sold for six months.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedAgreementNotToBeTransferredOrSoldForSixMonths" xlink:to="poai_StockIssuedAgreementNotToBeTransferredOrSoldForSixMonths-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedAgreementNotToBeTransferredOrSoldForThreeMonths" xlink:label="poai_StockIssuedAgreementNotToBeTransferredOrSoldForThreeMonths" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedAgreementNotToBeTransferredOrSoldForThreeMonths-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_StockIssuedAgreementNotToBeTransferredOrSoldForThreeMonths</link:label>
    <link:label xlink:label="poai_StockIssuedAgreementNotToBeTransferredOrSoldForThreeMonths-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Stock Issued, Agreement, Not to be Transferred or Sold For Three Months (in shares)</link:label>
    <link:label xlink:label="poai_StockIssuedAgreementNotToBeTransferredOrSoldForThreeMonths-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The number of shares issued under agreement that are not to be transferred or sold for three months.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedAgreementNotToBeTransferredOrSoldForThreeMonths" xlink:to="poai_StockIssuedAgreementNotToBeTransferredOrSoldForThreeMonths-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerShareBasicDistributed" xlink:label="us-gaap_EarningsPerShareBasicDistributed" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_EarningsPerShareBasicDistributed-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_EarningsPerShareBasicDistributed</link:label>
    <link:label xlink:label="us-gaap_EarningsPerShareBasicDistributed-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Loss per common share-basic and diluted (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareBasicDistributed" xlink:to="us-gaap_EarningsPerShareBasicDistributed-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="us-gaap_DerivativeInstrumentRiskAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DerivativeInstrumentRiskAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative Instrument [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeInstrumentRiskAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="us-gaap_DerivativeContractTypeDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DerivativeContractTypeDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative Contract [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="us-gaap_DerivativeContractTypeDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodValueInducementToConvertibleDebt" xlink:label="poai_StockIssuedDuringPeriodValueInducementToConvertibleDebt" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodValueInducementToConvertibleDebt-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Inducement shares issued pursuant to 2020 convertible debt and warrants</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodValueInducementToConvertibleDebt-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Value of stock issued for the inducement to convertible debt.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodValueInducementToConvertibleDebt" xlink:to="poai_StockIssuedDuringPeriodValueInducementToConvertibleDebt-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash flow from investing activities:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodSharesInducementToConvertibleDebt" xlink:label="poai_StockIssuedDuringPeriodSharesInducementToConvertibleDebt" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesInducementToConvertibleDebt-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Inducement shares issued pursuant to 2020 convertible debt and warrants (in shares)</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesInducementToConvertibleDebt-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The number of shares issued during the period for inducement to convertible debt.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodSharesInducementToConvertibleDebt" xlink:to="poai_StockIssuedDuringPeriodSharesInducementToConvertibleDebt-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerShareTextBlock" xlink:label="us-gaap_EarningsPerShareTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_EarningsPerShareTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Earnings Per Share [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareTextBlock" xlink:to="us-gaap_EarningsPerShareTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ConversionOfPromissoryNoteIntoCommonStockMember" xlink:label="poai_ConversionOfPromissoryNoteIntoCommonStockMember" xlink:type="locator"/>
    <link:label xlink:label="poai_ConversionOfPromissoryNoteIntoCommonStockMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Conversion of Promissory Note Into Common Stock [Member]</link:label>
    <link:label xlink:label="poai_ConversionOfPromissoryNoteIntoCommonStockMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the conversion of promissory note into common stock.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ConversionOfPromissoryNoteIntoCommonStockMember" xlink:to="poai_ConversionOfPromissoryNoteIntoCommonStockMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncreaseDecreaseInOtherOperatingLiabilities</link:label>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Other liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_Warrants2019Member" xlink:label="poai_Warrants2019Member" xlink:type="locator"/>
    <link:label xlink:label="poai_Warrants2019Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants 2019 [Member]</link:label>
    <link:label xlink:label="poai_Warrants2019Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to warrants.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_Warrants2019Member" xlink:to="poai_Warrants2019Member-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ProceedsFromIssuanceOrSaleOfEquityNetOfStockIssuanceCosts" xlink:label="poai_ProceedsFromIssuanceOrSaleOfEquityNetOfStockIssuanceCosts" xlink:type="locator"/>
    <link:label xlink:label="poai_ProceedsFromIssuanceOrSaleOfEquityNetOfStockIssuanceCosts-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Net proceeds</link:label>
    <link:label xlink:label="poai_ProceedsFromIssuanceOrSaleOfEquityNetOfStockIssuanceCosts-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Issuance of common stock, prefunded warrants, warrants and exchange of warrants, net</link:label>
    <link:label xlink:label="poai_ProceedsFromIssuanceOrSaleOfEquityNetOfStockIssuanceCosts-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Proceeds from Issuance or Sale of Equity, Net of Stock Issuance Costs</link:label>
    <link:label xlink:label="poai_ProceedsFromIssuanceOrSaleOfEquityNetOfStockIssuanceCosts-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The cash inflow from the issuance of common stock, preferred stock, treasury stock, stock options, warrants and other types of equity, net of issuance costs.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ProceedsFromIssuanceOrSaleOfEquityNetOfStockIssuanceCosts" xlink:to="poai_ProceedsFromIssuanceOrSaleOfEquityNetOfStockIssuanceCosts-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockOptions2019Member" xlink:label="poai_StockOptions2019Member" xlink:type="locator"/>
    <link:label xlink:label="poai_StockOptions2019Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Options 2019 [Member]</link:label>
    <link:label xlink:label="poai_StockOptions2019Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to stock options.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockOptions2019Member" xlink:to="poai_StockOptions2019Member-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:label="us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RelatedPartyTransactionsDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Related Party Transactions Disclosure [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:to="us-gaap_RelatedPartyTransactionsDisclosureTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income tax benefit</link:label>
    <link:label xlink:label="us-gaap_IncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Income Tax Expense (Benefit), Total</link:label>
    <link:label xlink:label="us-gaap_IncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:type="resource" xml:lang="en-US">Total income tax benefit</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxExpenseBenefit-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accrued expenses</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilities-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShortTermDebtTypeAxis" xlink:label="us-gaap_ShortTermDebtTypeAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShortTermDebtTypeAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Short-term Debt, Type [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermDebtTypeAxis" xlink:to="us-gaap_ShortTermDebtTypeAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShortTermDebtTypeDomain" xlink:label="us-gaap_ShortTermDebtTypeDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShortTermDebtTypeDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Short-term Debt, Type [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermDebtTypeDomain" xlink:to="us-gaap_ShortTermDebtTypeDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherNonoperatingGainsLosses" xlink:label="us-gaap_OtherNonoperatingGainsLosses" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OtherNonoperatingGainsLosses-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other income</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNonoperatingGainsLosses" xlink:to="us-gaap_OtherNonoperatingGainsLosses-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accounts payable</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsPayable" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainLossOnDerivativeInstrumentsNetPretax" xlink:label="us-gaap_GainLossOnDerivativeInstrumentsNetPretax" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_GainLossOnDerivativeInstrumentsNetPretax-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Gain on derivative instruments</link:label>
    <link:label xlink:label="us-gaap_GainLossOnDerivativeInstrumentsNetPretax-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Gain (Loss) on Derivative Instruments, Net, Pretax, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnDerivativeInstrumentsNetPretax" xlink:to="us-gaap_GainLossOnDerivativeInstrumentsNetPretax-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodAxis" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtInstrumentRedemptionPeriodAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Redemption, Period [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentRedemptionPeriodAxis" xlink:to="us-gaap_DebtInstrumentRedemptionPeriodAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtInstrumentRedemptionPeriodDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Redemption, Period [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentRedemptionPeriodDomain" xlink:to="us-gaap_DebtInstrumentRedemptionPeriodDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount" xlink:label="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount</link:label>
    <link:label xlink:label="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Defined Contribution Plan, Employer Discretionary Contribution Amount</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount" xlink:to="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ValuationAndAccountingForStockOptionsAndWarrantsPolicyPolicyTextBlock" xlink:label="poai_ValuationAndAccountingForStockOptionsAndWarrantsPolicyPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="poai_ValuationAndAccountingForStockOptionsAndWarrantsPolicyPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Valuation and Accounting for Stock Options and Warrants, Policy [Policy Text Block]</link:label>
    <link:label xlink:label="poai_ValuationAndAccountingForStockOptionsAndWarrantsPolicyPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Disclosure of the accounting policy for determining the valuation of options and warrants.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ValuationAndAccountingForStockOptionsAndWarrantsPolicyPolicyTextBlock" xlink:to="poai_ValuationAndAccountingForStockOptionsAndWarrantsPolicyPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="us-gaap_GeneralAndAdministrativeExpense" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_GeneralAndAdministrativeExpense-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">General and administrative expense</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GeneralAndAdministrativeExpense" xlink:to="us-gaap_GeneralAndAdministrativeExpense-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PropertyPlantAndEquipmentUsefulLifeTableTextBlock" xlink:label="poai_PropertyPlantAndEquipmentUsefulLifeTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="poai_PropertyPlantAndEquipmentUsefulLifeTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property Plant and Equipment Useful Life [Table Text Block]</link:label>
    <link:label xlink:label="poai_PropertyPlantAndEquipmentUsefulLifeTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the schedule of property, plant and equipment useful life.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PropertyPlantAndEquipmentUsefulLifeTableTextBlock" xlink:to="poai_PropertyPlantAndEquipmentUsefulLifeTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SkylineMedicalEuropesOfficesLeaseOfficeSpaceMember" xlink:label="poai_SkylineMedicalEuropesOfficesLeaseOfficeSpaceMember" xlink:type="locator"/>
    <link:label xlink:label="poai_SkylineMedicalEuropesOfficesLeaseOfficeSpaceMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Skyline Medical Europe's Offices Lease, Office Space [Member]</link:label>
    <link:label xlink:label="poai_SkylineMedicalEuropesOfficesLeaseOfficeSpaceMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the space used for offices at Skyline Medical Europe's offices.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SkylineMedicalEuropesOfficesLeaseOfficeSpaceMember" xlink:to="poai_SkylineMedicalEuropesOfficesLeaseOfficeSpaceMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:label="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent</link:label>
    <link:label xlink:label="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:to="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SkylineMedicalEuropesOfficesLeaseStorageSpaceMember" xlink:label="poai_SkylineMedicalEuropesOfficesLeaseStorageSpaceMember" xlink:type="locator"/>
    <link:label xlink:label="poai_SkylineMedicalEuropesOfficesLeaseStorageSpaceMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Skyline Medical Europe's Offices Lease, Storage Space [Member]</link:label>
    <link:label xlink:label="poai_SkylineMedicalEuropesOfficesLeaseStorageSpaceMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the space used for storage at Skyline Medical Europe's offices.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SkylineMedicalEuropesOfficesLeaseStorageSpaceMember" xlink:to="poai_SkylineMedicalEuropesOfficesLeaseStorageSpaceMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_DemoEquipmentMember" xlink:label="poai_DemoEquipmentMember" xlink:type="locator"/>
    <link:label xlink:label="poai_DemoEquipmentMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Demo Equipment [Member]</link:label>
    <link:label xlink:label="poai_DemoEquipmentMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Tangible personal property used in the demo process.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_DemoEquipmentMember" xlink:to="poai_DemoEquipmentMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch" xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch</link:label>
    <link:label xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Defined Contribution Plan, Employer Matching Contribution, Percent of Match</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch" xlink:to="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ManufacturingToolingMember" xlink:label="poai_ManufacturingToolingMember" xlink:type="locator"/>
    <link:label xlink:label="poai_ManufacturingToolingMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Manufacturing Tooling [Member]</link:label>
    <link:label xlink:label="poai_ManufacturingToolingMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Tools commonly used in the manufacturing of goods.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ManufacturingToolingMember" xlink:to="poai_ManufacturingToolingMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash and cash equivalents</link:label>
    <link:label xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cash and Cash Equivalents, at Carrying Value, Ending Balance</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentIncreaseDecreaseForPeriodNet" xlink:label="us-gaap_DebtInstrumentIncreaseDecreaseForPeriodNet" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtInstrumentIncreaseDecreaseForPeriodNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DebtInstrumentIncreaseDecreaseForPeriodNet</link:label>
    <link:label xlink:label="us-gaap_DebtInstrumentIncreaseDecreaseForPeriodNet-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Instrument, Increase (Decrease), Net, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentIncreaseDecreaseForPeriodNet" xlink:to="us-gaap_DebtInstrumentIncreaseDecreaseForPeriodNet-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentConvertibleThresholdTradingDays" xlink:label="us-gaap_DebtInstrumentConvertibleThresholdTradingDays" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtInstrumentConvertibleThresholdTradingDays-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DebtInstrumentConvertibleThresholdTradingDays</link:label>
    <link:label xlink:label="us-gaap_DebtInstrumentConvertibleThresholdTradingDays-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Instrument, Convertible, Threshold Trading Days</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentConvertibleThresholdTradingDays" xlink:to="us-gaap_DebtInstrumentConvertibleThresholdTradingDays-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisedWeightedAverageGrantDateFairValue" xlink:label="poai_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisedWeightedAverageGrantDateFairValue" xlink:type="locator"/>
    <link:label xlink:label="poai_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisedWeightedAverageGrantDateFairValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisedWeightedAverageGrantDateFairValue</link:label>
    <link:label xlink:label="poai_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisedWeightedAverageGrantDateFairValue-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Average Exercise Price Exercised (in dollars per share)</link:label>
    <link:label xlink:label="poai_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisedWeightedAverageGrantDateFairValue-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were exercised during the current period.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisedWeightedAverageGrantDateFairValue" xlink:to="poai_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisedWeightedAverageGrantDateFairValue-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentConvertibleConversionPrice1" xlink:label="us-gaap_DebtInstrumentConvertibleConversionPrice1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtInstrumentConvertibleConversionPrice1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DebtInstrumentConvertibleConversionPrice1</link:label>
    <link:label xlink:label="us-gaap_DebtInstrumentConvertibleConversionPrice1-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Instrument, Convertible, Conversion Price (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentConvertibleConversionPrice1" xlink:to="us-gaap_DebtInstrumentConvertibleConversionPrice1-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AllocatedShareBasedCompensationExpense-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_AllocatedShareBasedCompensationExpense</link:label>
    <link:label xlink:label="us-gaap_AllocatedShareBasedCompensationExpense-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Payment Arrangement, Expense</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllocatedShareBasedCompensationExpense" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings</link:label>
    <link:label xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Gain recognized to revalue derivative instrument at fair value</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag" xlink:type="locator"/>
    <link:label xlink:label="dei_AmendmentFlag-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Amendment Flag</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AmendmentFlag" xlink:to="dei_AmendmentFlag-label" xlink:type="arc"/>
	<link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_AuditorName" xlink:label="dei_AuditorName" xlink:type="locator"/>
    <link:label xlink:label="dei_AuditorName-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Auditor Name</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AuditorName" xlink:to="dei_AuditorName-label" xlink:type="arc"/>
	<link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_AuditorLocation" xlink:label="dei_AuditorLocation" xlink:type="locator"/>
    <link:label xlink:label="dei_AuditorLocation-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Auditor Location</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AuditorLocation" xlink:to="dei_AuditorLocation-label" xlink:type="arc"/>
	<link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_AuditorFirmId" xlink:label="dei_AuditorFirmId" xlink:type="locator"/>
    <link:label xlink:label="dei_AuditorFirmId-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Auditor Firm ID</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AuditorFirmId" xlink:to="dei_AuditorFirmId-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SeriesEConvertiblePreferredStockMember" xlink:label="poai_SeriesEConvertiblePreferredStockMember" xlink:type="locator"/>
    <link:label xlink:label="poai_SeriesEConvertiblePreferredStockMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Series E Convertible Preferred Stock [Member]</link:label>
    <link:label xlink:label="poai_SeriesEConvertiblePreferredStockMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information pertaining to Series E Convertible Preferred Stock.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SeriesEConvertiblePreferredStockMember" xlink:to="poai_SeriesEConvertiblePreferredStockMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_CityAreaCode" xlink:label="dei_CityAreaCode" xlink:type="locator"/>
    <link:label xlink:label="dei_CityAreaCode-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">City Area Code</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CityAreaCode" xlink:to="dei_CityAreaCode-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UseOfEstimates" xlink:label="us-gaap_UseOfEstimates" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_UseOfEstimates-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Use of Estimates, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UseOfEstimates" xlink:to="us-gaap_UseOfEstimates-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">New Accounting Pronouncements, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:to="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_RelatedPartyTransactionMonthlyCashPayment" xlink:label="poai_RelatedPartyTransactionMonthlyCashPayment" xlink:type="locator"/>
    <link:label xlink:label="poai_RelatedPartyTransactionMonthlyCashPayment-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_RelatedPartyTransactionMonthlyCashPayment</link:label>
    <link:label xlink:label="poai_RelatedPartyTransactionMonthlyCashPayment-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Monthly Cash Payment</link:label>
    <link:label xlink:label="poai_RelatedPartyTransactionMonthlyCashPayment-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The amount of monthly cash payment made to a related party.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_RelatedPartyTransactionMonthlyCashPayment" xlink:to="poai_RelatedPartyTransactionMonthlyCashPayment-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:label="us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PriorPeriodReclassificationAdjustmentDescription-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Reclassification, Comparability Adjustment [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:to="us-gaap_PriorPeriodReclassificationAdjustmentDescription-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_IncreaseInOperatingLeaseRightOfAssetAndLeaseLiabilityDueToLeaseModification" xlink:label="poai_IncreaseInOperatingLeaseRightOfAssetAndLeaseLiabilityDueToLeaseModification" xlink:type="locator"/>
    <link:label xlink:label="poai_IncreaseInOperatingLeaseRightOfAssetAndLeaseLiabilityDueToLeaseModification-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Increase to operating lease right of use asset and lease liability due to new and modified leases</link:label>
    <link:label xlink:label="poai_IncreaseInOperatingLeaseRightOfAssetAndLeaseLiabilityDueToLeaseModification-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents increase in operating lease right of asset and lease liability due to lease modification.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_IncreaseInOperatingLeaseRightOfAssetAndLeaseLiabilityDueToLeaseModification" xlink:to="poai_IncreaseInOperatingLeaseRightOfAssetAndLeaseLiabilityDueToLeaseModification-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:label="us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInContractWithCustomerLiability-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncreaseDecreaseInContractWithCustomerLiability</link:label>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInContractWithCustomerLiability-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Deferred revenue</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:to="us-gaap_IncreaseDecreaseInContractWithCustomerLiability-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesOutstanding" xlink:label="us-gaap_SharesOutstanding" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SharesOutstanding-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_SharesOutstanding</link:label>
    <link:label xlink:label="us-gaap_SharesOutstanding-label" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Balance (in shares)</link:label>
    <link:label xlink:label="us-gaap_SharesOutstanding-label" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Balance (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesOutstanding" xlink:to="us-gaap_SharesOutstanding-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CommonStockSharesOutstanding-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common stock, shares outstanding (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesOutstanding" xlink:to="us-gaap_CommonStockSharesOutstanding-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="us-gaap_PreferredStockSharesOutstanding" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PreferredStockSharesOutstanding-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred stock, shares outstanding (in shares)</link:label>
    <link:label xlink:label="us-gaap_PreferredStockSharesOutstanding-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Preferred Stock, Shares Outstanding, Ending Balance (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesOutstanding" xlink:to="us-gaap_PreferredStockSharesOutstanding-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_CurrentFiscalYearEndDate" xlink:label="dei_CurrentFiscalYearEndDate" xlink:type="locator"/>
    <link:label xlink:label="dei_CurrentFiscalYearEndDate-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Current Fiscal Year End Date</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CurrentFiscalYearEndDate" xlink:to="dei_CurrentFiscalYearEndDate-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NotesReceivableNet" xlink:label="us-gaap_NotesReceivableNet" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NotesReceivableNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_NotesReceivableNet</link:label>
    <link:label xlink:label="us-gaap_NotesReceivableNet-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Financing Receivable, after Allowance for Credit Loss, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesReceivableNet" xlink:to="us-gaap_NotesReceivableNet-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DebtInstrumentInterestRateStatedPercentage</link:label>
    <link:label xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Instrument, Interest Rate, Stated Percentage</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets</link:label>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Prepaid expense and other assets</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:to="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Weighted average discount rate &#8211; operating leases</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:to="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="dei_DocumentFiscalPeriodFocus" xlink:type="locator"/>
    <link:label xlink:label="dei_DocumentFiscalPeriodFocus-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Fiscal Period Focus</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentFiscalPeriodFocus" xlink:to="dei_DocumentFiscalPeriodFocus-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_Warrants2018Member" xlink:label="poai_Warrants2018Member" xlink:type="locator"/>
    <link:label xlink:label="poai_Warrants2018Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants 2018 [Member]</link:label>
    <link:label xlink:label="poai_Warrants2018Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents warrants 2018.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_Warrants2018Member" xlink:to="poai_Warrants2018Member-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentFiscalYearFocus" xlink:label="dei_DocumentFiscalYearFocus" xlink:type="locator"/>
    <link:label xlink:label="dei_DocumentFiscalYearFocus-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Fiscal Year Focus</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentFiscalYearFocus" xlink:to="dei_DocumentFiscalYearFocus-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockOptions2018Member" xlink:label="poai_StockOptions2018Member" xlink:type="locator"/>
    <link:label xlink:label="poai_StockOptions2018Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Options 2018 [Member]</link:label>
    <link:label xlink:label="poai_StockOptions2018Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the stock options in 2018.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockOptions2018Member" xlink:to="poai_StockOptions2018Member-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LeaseCostTableTextBlock" xlink:label="us-gaap_LeaseCostTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LeaseCostTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lease, Cost [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseCostTableTextBlock" xlink:to="us-gaap_LeaseCostTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentPeriodEndDate" xlink:label="dei_DocumentPeriodEndDate" xlink:type="locator"/>
    <link:label xlink:label="dei_DocumentPeriodEndDate-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Period End Date</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentPeriodEndDate" xlink:to="dei_DocumentPeriodEndDate-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Weighted average remaining lease term &#8211; operating leases in years (Year)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:to="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityFileNumber" xlink:label="dei_EntityFileNumber" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityFileNumber-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity File Number</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityFileNumber" xlink:to="dei_EntityFileNumber-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_CytoBioscienceMember" xlink:label="poai_CytoBioscienceMember" xlink:type="locator"/>
    <link:label xlink:label="poai_CytoBioscienceMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">CytoBioscience [Member]</link:label>
    <link:label xlink:label="poai_CytoBioscienceMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information pertaining to CytoBioscience, Inc.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_CytoBioscienceMember" xlink:to="poai_CytoBioscienceMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityEmergingGrowthCompany" xlink:label="dei_EntityEmergingGrowthCompany" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityEmergingGrowthCompany-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Emerging Growth Company</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityEmergingGrowthCompany" xlink:to="dei_EntityEmergingGrowthCompany-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="us-gaap_DebtInstrumentFaceAmount" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtInstrumentFaceAmount-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Notes Payable, Gross</link:label>
    <link:label xlink:label="us-gaap_DebtInstrumentFaceAmount-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DebtInstrumentFaceAmount</link:label>
    <link:label xlink:label="us-gaap_DebtInstrumentFaceAmount-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Instrument, Face Amount</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentFaceAmount" xlink:to="us-gaap_DebtInstrumentFaceAmount-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentType" xlink:label="dei_DocumentType" xlink:type="locator"/>
    <link:label xlink:label="dei_DocumentType-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Type</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentType" xlink:to="dei_DocumentType-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_GainsLossesOnExtinguishmentOfDebt</link:label>
    <link:label xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Gain (Loss) on Extinguishment of Debt, Total</link:label>
    <link:label xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Gain on extinguishment of PPP loan</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:to="us-gaap_GainsLossesOnExtinguishmentOfDebt-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_AdjustmentsToAdditionalPaidInCapitalRepricingAndReclassificationOfWarrants" xlink:label="poai_AdjustmentsToAdditionalPaidInCapitalRepricingAndReclassificationOfWarrants" xlink:type="locator"/>
    <link:label xlink:label="poai_AdjustmentsToAdditionalPaidInCapitalRepricingAndReclassificationOfWarrants-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Repricing and Reclassification of warrants issued pursuant to convertible debt</link:label>
    <link:label xlink:label="poai_AdjustmentsToAdditionalPaidInCapitalRepricingAndReclassificationOfWarrants-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents repricing and reclassification of warrants for adjustments to additional paid in capital.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_AdjustmentsToAdditionalPaidInCapitalRepricingAndReclassificationOfWarrants" xlink:to="poai_AdjustmentsToAdditionalPaidInCapitalRepricingAndReclassificationOfWarrants-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntitySmallBusiness" xlink:label="dei_EntitySmallBusiness" xlink:type="locator"/>
    <link:label xlink:label="dei_EntitySmallBusiness-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Small Business</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntitySmallBusiness" xlink:to="dei_EntitySmallBusiness-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityShellCompany" xlink:label="dei_EntityShellCompany" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityShellCompany-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Shell Company</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityShellCompany" xlink:to="dei_EntityShellCompany-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentInformationLineItems" xlink:label="dei_DocumentInformationLineItems" xlink:type="locator"/>
    <link:label xlink:label="dei_DocumentInformationLineItems-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Information [Line Items]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentInformationLineItems-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedForDebtMember" xlink:label="poai_StockIssuedForDebtMember" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedForDebtMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Issued for Debt [Member]</link:label>
    <link:label xlink:label="poai_StockIssuedForDebtMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to stock issued for debt.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedForDebtMember" xlink:to="poai_StockIssuedForDebtMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentInformationTable" xlink:label="dei_DocumentInformationTable" xlink:type="locator"/>
    <link:label xlink:label="dei_DocumentInformationTable-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Information [Table]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentInformationTable" xlink:to="dei_DocumentInformationTable-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedForConvertibleDebtMember" xlink:label="poai_StockIssuedForConvertibleDebtMember" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedForConvertibleDebtMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Issued for Convertible Debt [Member]</link:label>
    <link:label xlink:label="poai_StockIssuedForConvertibleDebtMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to stock issued for convertible debt.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedForConvertibleDebtMember" xlink:to="poai_StockIssuedForConvertibleDebtMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_FixedAssetsAcquiredForNotesReceivableAndCommonStock" xlink:label="poai_FixedAssetsAcquiredForNotesReceivableAndCommonStock" xlink:type="locator"/>
    <link:label xlink:label="poai_FixedAssetsAcquiredForNotesReceivableAndCommonStock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fixed assets acquired for notes receivable and common stock</link:label>
    <link:label xlink:label="poai_FixedAssetsAcquiredForNotesReceivableAndCommonStock-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fixed Assets Acquired for Notes Receivable and Common Stock</link:label>
    <link:label xlink:label="poai_FixedAssetsAcquiredForNotesReceivableAndCommonStock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The value of fixed assets acquired for notes receivable and common stock.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_FixedAssetsAcquiredForNotesReceivableAndCommonStock" xlink:to="poai_FixedAssetsAcquiredForNotesReceivableAndCommonStock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AreaOfRealEstateProperty" xlink:label="us-gaap_AreaOfRealEstateProperty" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AreaOfRealEstateProperty-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_AreaOfRealEstateProperty</link:label>
    <link:label xlink:label="us-gaap_AreaOfRealEstateProperty-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Area of Real Estate Property (Square Foot)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AreaOfRealEstateProperty" xlink:to="us-gaap_AreaOfRealEstateProperty-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityPublicFloat" xlink:label="dei_EntityPublicFloat" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityPublicFloat-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Public Float</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityPublicFloat" xlink:to="dei_EntityPublicFloat-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityFilerCategory" xlink:label="dei_EntityFilerCategory" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityFilerCategory-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Filer Category</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityFilerCategory" xlink:to="dei_EntityFilerCategory-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="us-gaap_DebtInstrumentAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtInstrumentAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityCurrentReportingStatus" xlink:label="dei_EntityCurrentReportingStatus" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityCurrentReportingStatus-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Current Reporting Status</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCurrentReportingStatus" xlink:to="dei_EntityCurrentReportingStatus-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="us-gaap_DebtInstrumentNameDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtInstrumentNameDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Name [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentNameDomain" xlink:to="us-gaap_DebtInstrumentNameDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityVoluntaryFilers" xlink:label="dei_EntityVoluntaryFilers" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityVoluntaryFilers-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Voluntary Filers</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityVoluntaryFilers" xlink:to="dei_EntityVoluntaryFilers-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_BusinessCombinationAcquisitionRelatedCosts-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_BusinessCombinationAcquisitionRelatedCosts</link:label>
    <link:label xlink:label="us-gaap_BusinessCombinationAcquisitionRelatedCosts-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Business Combination, Acquisition Related Costs</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:to="us-gaap_BusinessCombinationAcquisitionRelatedCosts-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_GainLossOnNoteReceivableAssetPurchaseAgreement" xlink:label="poai_GainLossOnNoteReceivableAssetPurchaseAgreement" xlink:type="locator"/>
    <link:label xlink:label="poai_GainLossOnNoteReceivableAssetPurchaseAgreement-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_GainLossOnNoteReceivableAssetPurchaseAgreement</link:label>
    <link:label xlink:label="poai_GainLossOnNoteReceivableAssetPurchaseAgreement-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Gain on note receivable associated with asset purchase agreement</link:label>
    <link:label xlink:label="poai_GainLossOnNoteReceivableAssetPurchaseAgreement-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The amount of gain (loss) on note receivable from asset purchase agreements.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_GainLossOnNoteReceivableAssetPurchaseAgreement" xlink:to="poai_GainLossOnNoteReceivableAssetPurchaseAgreement-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityWellKnownSeasonedIssuer" xlink:label="dei_EntityWellKnownSeasonedIssuer" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityWellKnownSeasonedIssuer-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Well-known Seasoned Issuer</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityWellKnownSeasonedIssuer" xlink:to="dei_EntityWellKnownSeasonedIssuer-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsFinitelived" xlink:label="us-gaap_ImpairmentOfIntangibleAssetsFinitelived" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ImpairmentOfIntangibleAssetsFinitelived-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Impairment, finite</link:label>
    <link:label xlink:label="us-gaap_ImpairmentOfIntangibleAssetsFinitelived-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ImpairmentOfIntangibleAssetsFinitelived</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ImpairmentOfIntangibleAssetsFinitelived" xlink:to="us-gaap_ImpairmentOfIntangibleAssetsFinitelived-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative instrument recognized</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PaycheckProtectionProgramCaresActMember" xlink:label="poai_PaycheckProtectionProgramCaresActMember" xlink:type="locator"/>
    <link:label xlink:label="poai_PaycheckProtectionProgramCaresActMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Paycheck Protection Program CARES Act [Member]</link:label>
    <link:label xlink:label="poai_PaycheckProtectionProgramCaresActMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents loan designed to provide funds for small businesses to keep their employees on the payroll.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PaycheckProtectionProgramCaresActMember" xlink:to="poai_PaycheckProtectionProgramCaresActMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_FixedAssetsAcquiredForFinancingArrangements" xlink:label="poai_FixedAssetsAcquiredForFinancingArrangements" xlink:type="locator"/>
    <link:label xlink:label="poai_FixedAssetsAcquiredForFinancingArrangements-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fixed assets acquired for financing arrangements</link:label>
    <link:label xlink:label="poai_FixedAssetsAcquiredForFinancingArrangements-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The value of fixed assets acquired for financing arrangements.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_FixedAssetsAcquiredForFinancingArrangements" xlink:to="poai_FixedAssetsAcquiredForFinancingArrangements-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsReceivableNet" xlink:label="us-gaap_AccountsReceivableNet" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AccountsReceivableNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_AccountsReceivableNet</link:label>
    <link:label xlink:label="us-gaap_AccountsReceivableNet-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accounts Receivable, after Allowance for Credit Loss, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsReceivableNet" xlink:to="us-gaap_AccountsReceivableNet-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_Warrants2020Member" xlink:label="poai_Warrants2020Member" xlink:type="locator"/>
    <link:label xlink:label="poai_Warrants2020Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants 2020 [Member]</link:label>
    <link:label xlink:label="poai_Warrants2020Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to warrants 2020.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_Warrants2020Member" xlink:to="poai_Warrants2020Member-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill" xlink:label="us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Impairment, indefinite</link:label>
    <link:label xlink:label="us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Loss on intangible impairment</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill" xlink:to="us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ProceedsFromIssuanceOfStockPursuantToEquityLine" xlink:label="poai_ProceedsFromIssuanceOfStockPursuantToEquityLine" xlink:type="locator"/>
    <link:label xlink:label="poai_ProceedsFromIssuanceOfStockPursuantToEquityLine-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Proceeds from issuance of stock pursuant to equity line</link:label>
    <link:label xlink:label="poai_ProceedsFromIssuanceOfStockPursuantToEquityLine-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The cash inflow from the issuance of stock pursuant to equity line.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ProceedsFromIssuanceOfStockPursuantToEquityLine" xlink:to="poai_ProceedsFromIssuanceOfStockPursuantToEquityLine-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillImpairmentLoss" xlink:label="us-gaap_GoodwillImpairmentLoss" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_GoodwillImpairmentLoss-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Loss on goodwill impairment</link:label>
    <link:label xlink:label="us-gaap_GoodwillImpairmentLoss-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Goodwill, Impairment Loss</link:label>
    <link:label xlink:label="us-gaap_GoodwillImpairmentLoss-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Impairment</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillImpairmentLoss" xlink:to="us-gaap_GoodwillImpairmentLoss-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants issued pursuant to 2020 convertible debt</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ConvertiblePreferredStockConversionRate" xlink:label="poai_ConvertiblePreferredStockConversionRate" xlink:type="locator"/>
    <link:label xlink:label="poai_ConvertiblePreferredStockConversionRate-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_ConvertiblePreferredStockConversionRate</link:label>
    <link:label xlink:label="poai_ConvertiblePreferredStockConversionRate-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Convertible Preferred Stock, Conversion Rate</link:label>
    <link:label xlink:label="poai_ConvertiblePreferredStockConversionRate-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The percentage of common stock for each share of convertible preferred stock that is converted.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ConvertiblePreferredStockConversionRate" xlink:to="poai_ConvertiblePreferredStockConversionRate-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ABAndAgentWarrantsPriorToReclassificationMember" xlink:label="poai_ABAndAgentWarrantsPriorToReclassificationMember" xlink:type="locator"/>
    <link:label xlink:label="poai_ABAndAgentWarrantsPriorToReclassificationMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">A, B and Agent Warrants, Prior to Reclassification [Member]</link:label>
    <link:label xlink:label="poai_ABAndAgentWarrantsPriorToReclassificationMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to A, B and Agent warrants, prior to reclassificaiton.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ABAndAgentWarrantsPriorToReclassificationMember" xlink:to="poai_ABAndAgentWarrantsPriorToReclassificationMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_DebtIssuedInSeptember2018September2019AndFebruary2020Member" xlink:label="poai_DebtIssuedInSeptember2018September2019AndFebruary2020Member" xlink:type="locator"/>
    <link:label xlink:label="poai_DebtIssuedInSeptember2018September2019AndFebruary2020Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Issued in September 2018, September, 2019, and February 2020 [Member]</link:label>
    <link:label xlink:label="poai_DebtIssuedInSeptember2018September2019AndFebruary2020Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to debt issued in September 2018, September 2019, and February 2020.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_DebtIssuedInSeptember2018September2019AndFebruary2020Member" xlink:to="poai_DebtIssuedInSeptember2018September2019AndFebruary2020Member-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncreaseDecreaseInAccountsReceivable</link:label>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Accounts receivable</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:to="us-gaap_IncreaseDecreaseInAccountsReceivable-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue</link:label>
    <link:label xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Vesting expense and option repricing</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityTaxIdentificationNumber" xlink:label="dei_EntityTaxIdentificationNumber" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityTaxIdentificationNumber-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Tax Identification Number</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityTaxIdentificationNumber" xlink:to="dei_EntityTaxIdentificationNumber-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockOptions2020Member" xlink:label="poai_StockOptions2020Member" xlink:type="locator"/>
    <link:label xlink:label="poai_StockOptions2020Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Options 2020 [Member]</link:label>
    <link:label xlink:label="poai_StockOptions2020Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to stock options 2020.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockOptions2020Member" xlink:to="poai_StockOptions2020Member-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityCentralIndexKey-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Central Index Key</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCentralIndexKey" xlink:to="dei_EntityCentralIndexKey-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ConversionOfSeriesDPreferredStockToCommonStockMember" xlink:label="poai_ConversionOfSeriesDPreferredStockToCommonStockMember" xlink:type="locator"/>
    <link:label xlink:label="poai_ConversionOfSeriesDPreferredStockToCommonStockMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Conversion of Series D Preferred Stock to Common Stock [Member]</link:label>
    <link:label xlink:label="poai_ConversionOfSeriesDPreferredStockToCommonStockMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents conversion of series D preferred stock to common stock.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ConversionOfSeriesDPreferredStockToCommonStockMember" xlink:to="poai_ConversionOfSeriesDPreferredStockToCommonStockMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DepreciationAndAmortization" xlink:label="us-gaap_DepreciationAndAmortization" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DepreciationAndAmortization-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DepreciationAndAmortization</link:label>
    <link:label xlink:label="us-gaap_DepreciationAndAmortization-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Depreciation and Amortization</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationAndAmortization" xlink:to="us-gaap_DepreciationAndAmortization-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityRegistrantName" xlink:label="dei_EntityRegistrantName" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityRegistrantName-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Registrant Name</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityRegistrantName" xlink:to="dei_EntityRegistrantName-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_EquityInstrumentsIssuedForManagementAndConsulting" xlink:label="poai_EquityInstrumentsIssuedForManagementAndConsulting" xlink:type="locator"/>
    <link:label xlink:label="poai_EquityInstrumentsIssuedForManagementAndConsulting-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity instruments issued for management, consulting, and other</link:label>
    <link:label xlink:label="poai_EquityInstrumentsIssuedForManagementAndConsulting-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Value of share-based compensation granted to nonemployees, directos, management and other.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_EquityInstrumentsIssuedForManagementAndConsulting" xlink:to="poai_EquityInstrumentsIssuedForManagementAndConsulting-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityDomain" xlink:label="dei_EntityDomain" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityDomain" xlink:to="dei_EntityDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PromissoryNote2019ConversionFeatureAgentWarrantsMember" xlink:label="poai_PromissoryNote2019ConversionFeatureAgentWarrantsMember" xlink:type="locator"/>
    <link:label xlink:label="poai_PromissoryNote2019ConversionFeatureAgentWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Promissory Note 2019 Conversion Feature Agent Warrants [Member]</link:label>
    <link:label xlink:label="poai_PromissoryNote2019ConversionFeatureAgentWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to Promissory Note 2019 conversion feature agent warrants.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PromissoryNote2019ConversionFeatureAgentWarrantsMember" xlink:to="poai_PromissoryNote2019ConversionFeatureAgentWarrantsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_May2020OfferingMember" xlink:label="poai_May2020OfferingMember" xlink:type="locator"/>
    <link:label xlink:label="poai_May2020OfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">May 2020 Offering [Member]</link:label>
    <link:label xlink:label="poai_May2020OfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information related to May 2020 offering.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_May2020OfferingMember" xlink:to="poai_May2020OfferingMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_LegalEntityAxis" xlink:label="dei_LegalEntityAxis" xlink:type="locator"/>
    <link:label xlink:label="dei_LegalEntityAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Legal Entity [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_LegalEntityAxis" xlink:to="dei_LegalEntityAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SolubleMember" xlink:label="poai_SolubleMember" xlink:type="locator"/>
    <link:label xlink:label="poai_SolubleMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Soluble [Member]</link:label>
    <link:label xlink:label="poai_SolubleMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information related to Soluble.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SolubleMember" xlink:to="poai_SolubleMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SkylineMember" xlink:label="poai_SkylineMember" xlink:type="locator"/>
    <link:label xlink:label="poai_SkylineMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Skyline [Member]</link:label>
    <link:label xlink:label="poai_SkylineMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information related to Skyline.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SkylineMember" xlink:to="poai_SkylineMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityAddressAddressLine1" xlink:label="dei_EntityAddressAddressLine1" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityAddressAddressLine1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Address, Address Line One</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressAddressLine1" xlink:to="dei_EntityAddressAddressLine1-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_HelomicsOfficesMember" xlink:label="poai_HelomicsOfficesMember" xlink:type="locator"/>
    <link:label xlink:label="poai_HelomicsOfficesMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Helomics' Offices [Member]</link:label>
    <link:label xlink:label="poai_HelomicsOfficesMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the lease related to Helomics' offices.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_HelomicsOfficesMember" xlink:to="poai_HelomicsOfficesMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_DeferredTaxAssetsRightOfUseAssets" xlink:label="poai_DeferredTaxAssetsRightOfUseAssets" xlink:type="locator"/>
    <link:label xlink:label="poai_DeferredTaxAssetsRightOfUseAssets-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Right of use asset</link:label>
    <link:label xlink:label="poai_DeferredTaxAssetsRightOfUseAssets-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from right of use assets.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_DeferredTaxAssetsRightOfUseAssets" xlink:to="poai_DeferredTaxAssetsRightOfUseAssets-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses" xlink:label="us-gaap_FinancingReceivableAllowanceForCreditLosses" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FinancingReceivableAllowanceForCreditLosses-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_FinancingReceivableAllowanceForCreditLosses</link:label>
    <link:label xlink:label="us-gaap_FinancingReceivableAllowanceForCreditLosses-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Financing Receivable, Allowance for Credit Loss, Ending Balance</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinancingReceivableAllowanceForCreditLosses" xlink:to="us-gaap_FinancingReceivableAllowanceForCreditLosses-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="us-gaap_AmortizationOfIntangibleAssets" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AmortizationOfIntangibleAssets-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_AmortizationOfIntangibleAssets</link:label>
    <link:label xlink:label="us-gaap_AmortizationOfIntangibleAssets-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Amortization of Intangible Assets, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfIntangibleAssets" xlink:to="us-gaap_AmortizationOfIntangibleAssets-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityAddressCityOrTown" xlink:label="dei_EntityAddressCityOrTown" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityAddressCityOrTown-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Address, City or Town</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressCityOrTown" xlink:to="dei_EntityAddressCityOrTown-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityAddressPostalZipCode" xlink:label="dei_EntityAddressPostalZipCode" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityAddressPostalZipCode-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Address, Postal Zip Code</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressPostalZipCode" xlink:to="dei_EntityAddressPostalZipCode-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_CorporateOfficeMinnesotaMember" xlink:label="poai_CorporateOfficeMinnesotaMember" xlink:type="locator"/>
    <link:label xlink:label="poai_CorporateOfficeMinnesotaMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Corporate Office, Minnesota [Member]</link:label>
    <link:label xlink:label="poai_CorporateOfficeMinnesotaMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information pertaining to the corporate office in Eagan, Minnesota.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_CorporateOfficeMinnesotaMember" xlink:to="poai_CorporateOfficeMinnesotaMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityAddressStateOrProvince" xlink:label="dei_EntityAddressStateOrProvince" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityAddressStateOrProvince-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Address, State or Province</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressStateOrProvince" xlink:to="dei_EntityAddressStateOrProvince-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodSharesConvertiblePreferredSharesIssued" xlink:label="poai_StockIssuedDuringPeriodSharesConvertiblePreferredSharesIssued" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesConvertiblePreferredSharesIssued-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_StockIssuedDuringPeriodSharesConvertiblePreferredSharesIssued</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesConvertiblePreferredSharesIssued-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Stock Issued During Period, Shares, Convertible Preferred Shares Issued (in shares)</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesConvertiblePreferredSharesIssued-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Number of convertible preferred shares issued during the period.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodSharesConvertiblePreferredSharesIssued" xlink:to="poai_StockIssuedDuringPeriodSharesConvertiblePreferredSharesIssued-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_DefinedContributionPlanEmployerContributionAmount" xlink:label="poai_DefinedContributionPlanEmployerContributionAmount" xlink:type="locator"/>
    <link:label xlink:label="poai_DefinedContributionPlanEmployerContributionAmount-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_DefinedContributionPlanEmployerContributionAmount</link:label>
    <link:label xlink:label="poai_DefinedContributionPlanEmployerContributionAmount-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Defined Contribution Plan, Employer Contribution Amount</link:label>
    <link:label xlink:label="poai_DefinedContributionPlanEmployerContributionAmount-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amount of contributions made by an employer to a defined contribution plan.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_DefinedContributionPlanEmployerContributionAmount" xlink:to="poai_DefinedContributionPlanEmployerContributionAmount-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="dei_EntityCommonStockSharesOutstanding" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityCommonStockSharesOutstanding-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Common Stock, Shares Outstanding</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCommonStockSharesOutstanding" xlink:to="dei_EntityCommonStockSharesOutstanding-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_DerivativesDebtIssued" xlink:label="poai_DerivativesDebtIssued" xlink:type="locator"/>
    <link:label xlink:label="poai_DerivativesDebtIssued-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Put and conversion derivative from debt issuance and modification</link:label>
    <link:label xlink:label="poai_DerivativesDebtIssued-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The value of derivatives due to debt issuance.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_DerivativesDebtIssued" xlink:to="poai_DerivativesDebtIssued-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_AssetPurchaseAgreementWithInventabiotechAndItsSubsidiariesSolubleAndBiodethMember" xlink:label="poai_AssetPurchaseAgreementWithInventabiotechAndItsSubsidiariesSolubleAndBiodethMember" xlink:type="locator"/>
    <link:label xlink:label="poai_AssetPurchaseAgreementWithInventabiotechAndItsSubsidiariesSolubleAndBiodethMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Purchase Agreement with InventaBiotech and Its Subsidiaries, Soluble and BioDeth [Member]</link:label>
    <link:label xlink:label="poai_AssetPurchaseAgreementWithInventabiotechAndItsSubsidiariesSolubleAndBiodethMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information related to asset purchase agreement with InventaBiotech and its Subsidiaries, Soluble and BioDeth.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_AssetPurchaseAgreementWithInventabiotechAndItsSubsidiariesSolubleAndBiodethMember" xlink:to="poai_AssetPurchaseAgreementWithInventabiotechAndItsSubsidiariesSolubleAndBiodethMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PromissoryNote2020ConversionFeatureTrancheOneMember" xlink:label="poai_PromissoryNote2020ConversionFeatureTrancheOneMember" xlink:type="locator"/>
    <link:label xlink:label="poai_PromissoryNote2020ConversionFeatureTrancheOneMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Promissory Note 2020 Conversion Feature, Tranche One [Member]</link:label>
    <link:label xlink:label="poai_PromissoryNote2020ConversionFeatureTrancheOneMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to tranche one of the promissory note 2020 conversion feature.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PromissoryNote2020ConversionFeatureTrancheOneMember" xlink:to="poai_PromissoryNote2020ConversionFeatureTrancheOneMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PromissoryNote2020ConversionFeatureTrancheTwoMember" xlink:label="poai_PromissoryNote2020ConversionFeatureTrancheTwoMember" xlink:type="locator"/>
    <link:label xlink:label="poai_PromissoryNote2020ConversionFeatureTrancheTwoMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Promissory Note 2020 Conversion Feature, Tranche Two [Member]</link:label>
    <link:label xlink:label="poai_PromissoryNote2020ConversionFeatureTrancheTwoMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to the second trance of the promissory note 2020 conversion feature.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PromissoryNote2020ConversionFeatureTrancheTwoMember" xlink:to="poai_PromissoryNote2020ConversionFeatureTrancheTwoMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PromissoryNote2020ConversionFeatureTrancheThreeMember" xlink:label="poai_PromissoryNote2020ConversionFeatureTrancheThreeMember" xlink:type="locator"/>
    <link:label xlink:label="poai_PromissoryNote2020ConversionFeatureTrancheThreeMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Promissory Note 2020 Conversion Feature, Tranche Three [Member]</link:label>
    <link:label xlink:label="poai_PromissoryNote2020ConversionFeatureTrancheThreeMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information related to tranche three of conversion feature promissory note.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PromissoryNote2020ConversionFeatureTrancheThreeMember" xlink:to="poai_PromissoryNote2020ConversionFeatureTrancheThreeMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValuePurchaseOfAssets" xlink:label="us-gaap_StockIssuedDuringPeriodValuePurchaseOfAssets" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodValuePurchaseOfAssets-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares issued in connection with asset purchase agreement</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValuePurchaseOfAssets" xlink:to="us-gaap_StockIssuedDuringPeriodValuePurchaseOfAssets-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesPurchaseOfAssets" xlink:label="us-gaap_StockIssuedDuringPeriodSharesPurchaseOfAssets" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesPurchaseOfAssets-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares issued in connection with asset purchase agreement (in shares)</link:label>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesPurchaseOfAssets-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Stock Issued During Period, Shares, Purchase of Assets (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesPurchaseOfAssets" xlink:to="us-gaap_StockIssuedDuringPeriodSharesPurchaseOfAssets-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueOther" xlink:label="us-gaap_StockIssuedDuringPeriodValueOther" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodValueOther-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares issued pursuant to CEO note conversion and accrued interest and exchange agreement</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueOther" xlink:to="us-gaap_StockIssuedDuringPeriodValueOther-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesOther" xlink:label="us-gaap_StockIssuedDuringPeriodSharesOther" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesOther-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares issued pursuant to CEO note conversion and accrued interest and exchange agreement (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesOther" xlink:to="us-gaap_StockIssuedDuringPeriodSharesOther-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_HelomicsHoldingCorpMember" xlink:label="poai_HelomicsHoldingCorpMember" xlink:type="locator"/>
    <link:label xlink:label="poai_HelomicsHoldingCorpMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Helomics Holding Corp. [Member]</link:label>
    <link:label xlink:label="poai_HelomicsHoldingCorpMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information pertaining to Helomics Holding Corporation.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_HelomicsHoldingCorpMember" xlink:to="poai_HelomicsHoldingCorpMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_HelomicsSegmentMember" xlink:label="poai_HelomicsSegmentMember" xlink:type="locator"/>
    <link:label xlink:label="poai_HelomicsSegmentMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Helomics Segment [Member]</link:label>
    <link:label xlink:label="poai_HelomicsSegmentMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the Helomics segment.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_HelomicsSegmentMember" xlink:to="poai_HelomicsSegmentMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_WarrantForPromissoryNotesMember" xlink:label="poai_WarrantForPromissoryNotesMember" xlink:type="locator"/>
    <link:label xlink:label="poai_WarrantForPromissoryNotesMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrant for Promissory Notes [Member]</link:label>
    <link:label xlink:label="poai_WarrantForPromissoryNotesMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to the warrant for promissory notes.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantForPromissoryNotesMember" xlink:to="poai_WarrantForPromissoryNotesMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInInventories" xlink:label="us-gaap_IncreaseDecreaseInInventories" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInInventories-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncreaseDecreaseInInventories</link:label>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInInventories-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Inventories</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInInventories" xlink:to="us-gaap_IncreaseDecreaseInInventories-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_TradingSymbol" xlink:label="dei_TradingSymbol" xlink:type="locator"/>
    <link:label xlink:label="dei_TradingSymbol-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Trading Symbol</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_TradingSymbol" xlink:to="dei_TradingSymbol-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PromissoryNoteMember" xlink:label="poai_PromissoryNoteMember" xlink:type="locator"/>
    <link:label xlink:label="poai_PromissoryNoteMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Promissory Note [Member]</link:label>
    <link:label xlink:label="poai_PromissoryNoteMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to a promissory note.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PromissoryNoteMember" xlink:to="poai_PromissoryNoteMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_BorrowingsAgainstEquityLineMember" xlink:label="poai_BorrowingsAgainstEquityLineMember" xlink:type="locator"/>
    <link:label xlink:label="poai_BorrowingsAgainstEquityLineMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Borrowings Against Equity Line [Member]</link:label>
    <link:label xlink:label="poai_BorrowingsAgainstEquityLineMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the borrowings against the equity line purchase agreement.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_BorrowingsAgainstEquityLineMember" xlink:to="poai_BorrowingsAgainstEquityLineMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities" xlink:label="us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares issued pursuant to conversions</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities" xlink:to="us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ConversionOfBridgeLoanToCommonStockMember" xlink:label="poai_ConversionOfBridgeLoanToCommonStockMember" xlink:type="locator"/>
    <link:label xlink:label="poai_ConversionOfBridgeLoanToCommonStockMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Conversion of Bridge Loan to Common Stock [Member]</link:label>
    <link:label xlink:label="poai_ConversionOfBridgeLoanToCommonStockMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the conversion of bridge loan to common stock.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ConversionOfBridgeLoanToCommonStockMember" xlink:to="poai_ConversionOfBridgeLoanToCommonStockMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares issued pursuant to conversions (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:to="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_WarrantsIssuedInConnectionWithHelomicsAcquisitionMember" xlink:label="poai_WarrantsIssuedInConnectionWithHelomicsAcquisitionMember" xlink:type="locator"/>
    <link:label xlink:label="poai_WarrantsIssuedInConnectionWithHelomicsAcquisitionMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants Issued in Connection With Helomics Acquisition [Member]</link:label>
    <link:label xlink:label="poai_WarrantsIssuedInConnectionWithHelomicsAcquisitionMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to warrants issued in connection with Helomics acquisition.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantsIssuedInConnectionWithHelomicsAcquisitionMember" xlink:to="poai_WarrantsIssuedInConnectionWithHelomicsAcquisitionMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PromissoryNote2020ConversionFeatureMember" xlink:label="poai_PromissoryNote2020ConversionFeatureMember" xlink:type="locator"/>
    <link:label xlink:label="poai_PromissoryNote2020ConversionFeatureMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Promissory Note 2020 Conversion Feature [Member]</link:label>
    <link:label xlink:label="poai_PromissoryNote2020ConversionFeatureMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to Promissory Note 2020 conversion feature.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PromissoryNote2020ConversionFeatureMember" xlink:to="poai_PromissoryNote2020ConversionFeatureMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_LocalPhoneNumber" xlink:label="dei_LocalPhoneNumber" xlink:type="locator"/>
    <link:label xlink:label="dei_LocalPhoneNumber-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Local Phone Number</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_LocalPhoneNumber" xlink:to="dei_LocalPhoneNumber-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PromissoryNote2019ConversionFeatureMember" xlink:label="poai_PromissoryNote2019ConversionFeatureMember" xlink:type="locator"/>
    <link:label xlink:label="poai_PromissoryNote2019ConversionFeatureMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Promissory Note 2019 Conversion Feature [Member]</link:label>
    <link:label xlink:label="poai_PromissoryNote2019ConversionFeatureMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to Promissory Note 2019 conversion feature.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PromissoryNote2019ConversionFeatureMember" xlink:to="poai_PromissoryNote2019ConversionFeatureMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SaleOfStockRemainingAvailableBalance" xlink:label="poai_SaleOfStockRemainingAvailableBalance" xlink:type="locator"/>
    <link:label xlink:label="poai_SaleOfStockRemainingAvailableBalance-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_SaleOfStockRemainingAvailableBalance</link:label>
    <link:label xlink:label="poai_SaleOfStockRemainingAvailableBalance-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Sale of Stock, Remaining Available Balance</link:label>
    <link:label xlink:label="poai_SaleOfStockRemainingAvailableBalance-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The remaining available balance in a sale of stock agreement.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SaleOfStockRemainingAvailableBalance" xlink:to="poai_SaleOfStockRemainingAvailableBalance-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_WarrantsAndAgentWarrantsInConnectionWithJune2020WarrantMember" xlink:label="poai_WarrantsAndAgentWarrantsInConnectionWithJune2020WarrantMember" xlink:type="locator"/>
    <link:label xlink:label="poai_WarrantsAndAgentWarrantsInConnectionWithJune2020WarrantMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants and Agent Warrants In Connection With June 2020 Warrant [Member]</link:label>
    <link:label xlink:label="poai_WarrantsAndAgentWarrantsInConnectionWithJune2020WarrantMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents warrants and agent warrants in connection with June 2020 warrant.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantsAndAgentWarrantsInConnectionWithJune2020WarrantMember" xlink:to="poai_WarrantsAndAgentWarrantsInConnectionWithJune2020WarrantMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised</link:label>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Number of Shares Exercised (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TableTextBlock" xlink:label="us-gaap_TableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_TableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_TableTextBlock</link:label>
    <link:label xlink:label="us-gaap_TableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Notes Tables</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TableTextBlock" xlink:to="us-gaap_TableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_WarrantsAndAgentWarrantsInConnectionWithMay2020WarrantMember" xlink:label="poai_WarrantsAndAgentWarrantsInConnectionWithMay2020WarrantMember" xlink:type="locator"/>
    <link:label xlink:label="poai_WarrantsAndAgentWarrantsInConnectionWithMay2020WarrantMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants and Agent Warrants In Connection With May 2020 Warrant [Member]</link:label>
    <link:label xlink:label="poai_WarrantsAndAgentWarrantsInConnectionWithMay2020WarrantMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents warrants and agent warrants in connection with May 2020 warrant.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantsAndAgentWarrantsInConnectionWithMay2020WarrantMember" xlink:to="poai_WarrantsAndAgentWarrantsInConnectionWithMay2020WarrantMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainLossOnDispositionOfAssets1" xlink:label="us-gaap_GainLossOnDispositionOfAssets1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_GainLossOnDispositionOfAssets1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_GainLossOnDispositionOfAssets1</link:label>
    <link:label xlink:label="us-gaap_GainLossOnDispositionOfAssets1-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Loss on fixed asset disposal</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnDispositionOfAssets1" xlink:to="us-gaap_GainLossOnDispositionOfAssets1-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_DrSchwartzNoteOneMember" xlink:label="poai_DrSchwartzNoteOneMember" xlink:type="locator"/>
    <link:label xlink:label="poai_DrSchwartzNoteOneMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Dr. Schwartz Note, One [Member]</link:label>
    <link:label xlink:label="poai_DrSchwartzNoteOneMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the first tranche of Dr. Schwartz note.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_DrSchwartzNoteOneMember" xlink:to="poai_DrSchwartzNoteOneMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_BusinessAcquisitionRightToReclaimNumberOfShares" xlink:label="poai_BusinessAcquisitionRightToReclaimNumberOfShares" xlink:type="locator"/>
    <link:label xlink:label="poai_BusinessAcquisitionRightToReclaimNumberOfShares-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_BusinessAcquisitionRightToReclaimNumberOfShares</link:label>
    <link:label xlink:label="poai_BusinessAcquisitionRightToReclaimNumberOfShares-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Business Acquisition, Right to Reclaim, Number of Shares (in shares)</link:label>
    <link:label xlink:label="poai_BusinessAcquisitionRightToReclaimNumberOfShares-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents number of shares right to reclaim for business acquisition.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_BusinessAcquisitionRightToReclaimNumberOfShares" xlink:to="poai_BusinessAcquisitionRightToReclaimNumberOfShares-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Related Party [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RelatedPartyDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Related Party [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="us-gaap_RelatedPartyDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ClassOfWarrantOrRightPercentageOfSharesIssuedPursuantToExerciseOfExistingWarrant" xlink:label="poai_ClassOfWarrantOrRightPercentageOfSharesIssuedPursuantToExerciseOfExistingWarrant" xlink:type="locator"/>
    <link:label xlink:label="poai_ClassOfWarrantOrRightPercentageOfSharesIssuedPursuantToExerciseOfExistingWarrant-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_ClassOfWarrantOrRightPercentageOfSharesIssuedPursuantToExerciseOfExistingWarrant</link:label>
    <link:label xlink:label="poai_ClassOfWarrantOrRightPercentageOfSharesIssuedPursuantToExerciseOfExistingWarrant-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class of Warrant or Right, Percentage of Shares Issued Pursuant to Exercise of Existing Warrant</link:label>
    <link:label xlink:label="poai_ClassOfWarrantOrRightPercentageOfSharesIssuedPursuantToExerciseOfExistingWarrant-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents percentage of shares issued pursuant to exercise of existing warrant.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ClassOfWarrantOrRightPercentageOfSharesIssuedPursuantToExerciseOfExistingWarrant" xlink:to="poai_ClassOfWarrantOrRightPercentageOfSharesIssuedPursuantToExerciseOfExistingWarrant-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_June2020WarrantMember" xlink:label="poai_June2020WarrantMember" xlink:type="locator"/>
    <link:label xlink:label="poai_June2020WarrantMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">June 2020 Warrant [Member]</link:label>
    <link:label xlink:label="poai_June2020WarrantMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information related to June 2020 warrant.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_June2020WarrantMember" xlink:to="poai_June2020WarrantMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Vesting expense and option repricing (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:to="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_BridgeLoanWarrantsMember" xlink:label="poai_BridgeLoanWarrantsMember" xlink:type="locator"/>
    <link:label xlink:label="poai_BridgeLoanWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Bridge Loan Warrants [Member]</link:label>
    <link:label xlink:label="poai_BridgeLoanWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Warrants issued in connection with bridge loan.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_BridgeLoanWarrantsMember" xlink:to="poai_BridgeLoanWarrantsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ImpairmentOfIntangibleAssetsSoftwareAcquired" xlink:label="poai_ImpairmentOfIntangibleAssetsSoftwareAcquired" xlink:type="locator"/>
    <link:label xlink:label="poai_ImpairmentOfIntangibleAssetsSoftwareAcquired-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Loss on impairment of software acquired</link:label>
    <link:label xlink:label="poai_ImpairmentOfIntangibleAssetsSoftwareAcquired-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Impairment of Intangible Assets, Software Acquired</link:label>
    <link:label xlink:label="poai_ImpairmentOfIntangibleAssetsSoftwareAcquired-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Impairment expense &#8211; acquired software</link:label>
    <link:label xlink:label="poai_ImpairmentOfIntangibleAssetsSoftwareAcquired-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Impairment of software acquired.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ImpairmentOfIntangibleAssetsSoftwareAcquired" xlink:to="poai_ImpairmentOfIntangibleAssetsSoftwareAcquired-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PromissoryNoteTwoMember" xlink:label="poai_PromissoryNoteTwoMember" xlink:type="locator"/>
    <link:label xlink:label="poai_PromissoryNoteTwoMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Promissory Note, Two [Member]</link:label>
    <link:label xlink:label="poai_PromissoryNoteTwoMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the second tranche of the promissory note.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PromissoryNoteTwoMember" xlink:to="poai_PromissoryNoteTwoMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of Shares Issued (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WarrantsAndRightsOutstandingMeasurementInput" xlink:label="us-gaap_WarrantsAndRightsOutstandingMeasurementInput" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_WarrantsAndRightsOutstandingMeasurementInput-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants and Rights Outstanding, Measurement Input</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WarrantsAndRightsOutstandingMeasurementInput" xlink:to="us-gaap_WarrantsAndRightsOutstandingMeasurementInput-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Number of Shares Forfeited (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WarrantsAndRightsOutstandingTerm" xlink:label="us-gaap_WarrantsAndRightsOutstandingTerm" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_WarrantsAndRightsOutstandingTerm-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_WarrantsAndRightsOutstandingTerm</link:label>
    <link:label xlink:label="us-gaap_WarrantsAndRightsOutstandingTerm-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Warrants and Rights Outstanding, Term (Year)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WarrantsAndRightsOutstandingTerm" xlink:to="us-gaap_WarrantsAndRightsOutstandingTerm-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PromissoryNoteOneMember" xlink:label="poai_PromissoryNoteOneMember" xlink:type="locator"/>
    <link:label xlink:label="poai_PromissoryNoteOneMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Promissory Note, One [Member]</link:label>
    <link:label xlink:label="poai_PromissoryNoteOneMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The first tranche of the promissory note.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PromissoryNoteOneMember" xlink:to="poai_PromissoryNoteOneMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SellingAndMarketingExpense" xlink:label="us-gaap_SellingAndMarketingExpense" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SellingAndMarketingExpense-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sales and marketing expense</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SellingAndMarketingExpense" xlink:to="us-gaap_SellingAndMarketingExpense-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_WarrantsIssuedWithPromissoryNoteOneMember" xlink:label="poai_WarrantsIssuedWithPromissoryNoteOneMember" xlink:type="locator"/>
    <link:label xlink:label="poai_WarrantsIssuedWithPromissoryNoteOneMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants Issued With Promissory Note, One [Member]</link:label>
    <link:label xlink:label="poai_WarrantsIssuedWithPromissoryNoteOneMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the warrants issued with the first tranche of promissory note.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantsIssuedWithPromissoryNoteOneMember" xlink:to="poai_WarrantsIssuedWithPromissoryNoteOneMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Shares issued (in shares)</link:label>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares issued (in shares)</link:label>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Stock Issued During Period, Shares, New Issues (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PromissoryNoteExchangeAgreementMember" xlink:label="poai_PromissoryNoteExchangeAgreementMember" xlink:type="locator"/>
    <link:label xlink:label="poai_PromissoryNoteExchangeAgreementMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Promissory Note Exchange Agreement [Member]</link:label>
    <link:label xlink:label="poai_PromissoryNoteExchangeAgreementMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the promissory note exchange agreement.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PromissoryNoteExchangeAgreementMember" xlink:to="poai_PromissoryNoteExchangeAgreementMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingCostsAndExpenses" xlink:label="us-gaap_OperatingCostsAndExpenses" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingCostsAndExpenses-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operations expense</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingCostsAndExpenses" xlink:to="us-gaap_OperatingCostsAndExpenses-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_InvestorOfPromissoryNoteMember" xlink:label="poai_InvestorOfPromissoryNoteMember" xlink:type="locator"/>
    <link:label xlink:label="poai_InvestorOfPromissoryNoteMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Investor of Promissory Note [Member]</link:label>
    <link:label xlink:label="poai_InvestorOfPromissoryNoteMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the investor of the promissory note.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_InvestorOfPromissoryNoteMember" xlink:to="poai_InvestorOfPromissoryNoteMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueIssuedForServices" xlink:label="us-gaap_StockIssuedDuringPeriodValueIssuedForServices" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodValueIssuedForServices-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_StockIssuedDuringPeriodValueIssuedForServices</link:label>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodValueIssuedForServices-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share issuance to consultant and other</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueIssuedForServices" xlink:to="us-gaap_StockIssuedDuringPeriodValueIssuedForServices-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoryRawMaterialsNetOfReserves" xlink:label="us-gaap_InventoryRawMaterialsNetOfReserves" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_InventoryRawMaterialsNetOfReserves-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Raw materials</link:label>
    <link:label xlink:label="us-gaap_InventoryRawMaterialsNetOfReserves-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_InventoryRawMaterialsNetOfReserves</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryRawMaterialsNetOfReserves" xlink:to="us-gaap_InventoryRawMaterialsNetOfReserves-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_WarrantsIssuedWithPromissoryNoteMember" xlink:label="poai_WarrantsIssuedWithPromissoryNoteMember" xlink:type="locator"/>
    <link:label xlink:label="poai_WarrantsIssuedWithPromissoryNoteMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants Issued With Promissory Note [Member]</link:label>
    <link:label xlink:label="poai_WarrantsIssuedWithPromissoryNoteMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the warrants issued with the promissory note.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantsIssuedWithPromissoryNoteMember" xlink:to="poai_WarrantsIssuedWithPromissoryNoteMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" xlink:label="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share issuance to consultant and other (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" xlink:to="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_WarrantsIssuedWithPromissoryNoteTwoMember" xlink:label="poai_WarrantsIssuedWithPromissoryNoteTwoMember" xlink:type="locator"/>
    <link:label xlink:label="poai_WarrantsIssuedWithPromissoryNoteTwoMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants Issued With Promissory Note, Two [Member]</link:label>
    <link:label xlink:label="poai_WarrantsIssuedWithPromissoryNoteTwoMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the warrants issued with the second tranche of promissory note.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantsIssuedWithPromissoryNoteTwoMember" xlink:to="poai_WarrantsIssuedWithPromissoryNoteTwoMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_AgentWarrantsInConnectionWithJune2020WarrantMember" xlink:label="poai_AgentWarrantsInConnectionWithJune2020WarrantMember" xlink:type="locator"/>
    <link:label xlink:label="poai_AgentWarrantsInConnectionWithJune2020WarrantMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Agent Warrants In Connection With June 2020 Warrant [Member]</link:label>
    <link:label xlink:label="poai_AgentWarrantsInConnectionWithJune2020WarrantMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents agent warrants in connection with June 2020 warrant.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_AgentWarrantsInConnectionWithJune2020WarrantMember" xlink:to="poai_AgentWarrantsInConnectionWithJune2020WarrantMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LiabilitiesAndStockholdersEquity-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LiabilitiesAndStockholdersEquity</link:label>
    <link:label xlink:label="us-gaap_LiabilitiesAndStockholdersEquity-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total Liabilities and Stockholders' Equity</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoryFinishedGoodsNetOfReserves" xlink:label="us-gaap_InventoryFinishedGoodsNetOfReserves" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_InventoryFinishedGoodsNetOfReserves-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Finished goods</link:label>
    <link:label xlink:label="us-gaap_InventoryFinishedGoodsNetOfReserves-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_InventoryFinishedGoodsNetOfReserves</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryFinishedGoodsNetOfReserves" xlink:to="us-gaap_InventoryFinishedGoodsNetOfReserves-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_AssetPurchaseAgreementWithQuantitativeMedicineMember" xlink:label="poai_AssetPurchaseAgreementWithQuantitativeMedicineMember" xlink:type="locator"/>
    <link:label xlink:label="poai_AssetPurchaseAgreementWithQuantitativeMedicineMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Purchase Agreement With Quantitative Medicine [Member]</link:label>
    <link:label xlink:label="poai_AssetPurchaseAgreementWithQuantitativeMedicineMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents asset purchase agreement with Quantitative Medicine LLC.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_AssetPurchaseAgreementWithQuantitativeMedicineMember" xlink:to="poai_AssetPurchaseAgreementWithQuantitativeMedicineMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoryWorkInProcessNetOfReserves" xlink:label="us-gaap_InventoryWorkInProcessNetOfReserves" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_InventoryWorkInProcessNetOfReserves-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Work-In-Process</link:label>
    <link:label xlink:label="us-gaap_InventoryWorkInProcessNetOfReserves-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_InventoryWorkInProcessNetOfReserves</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryWorkInProcessNetOfReserves" xlink:to="us-gaap_InventoryWorkInProcessNetOfReserves-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Issuance of shares</link:label>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Stock Issued During Period, Value, New Issues</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:to="us-gaap_StockIssuedDuringPeriodValueNewIssues-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_CarnegieMellonUniversityMember" xlink:label="poai_CarnegieMellonUniversityMember" xlink:type="locator"/>
    <link:label xlink:label="poai_CarnegieMellonUniversityMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Carnegie Mellon University [Member]</link:label>
    <link:label xlink:label="poai_CarnegieMellonUniversityMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information related to Carnegie Mellon University.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_CarnegieMellonUniversityMember" xlink:to="poai_CarnegieMellonUniversityMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_WarrantIssuedInConnectionWithMay2020OfferingMember" xlink:label="poai_WarrantIssuedInConnectionWithMay2020OfferingMember" xlink:type="locator"/>
    <link:label xlink:label="poai_WarrantIssuedInConnectionWithMay2020OfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrant Issued in Connection With May 2020 Offering [Member]</link:label>
    <link:label xlink:label="poai_WarrantIssuedInConnectionWithMay2020OfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents warrants issued in connection with May 2020 offering.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantIssuedInConnectionWithMay2020OfferingMember" xlink:to="poai_WarrantIssuedInConnectionWithMay2020OfferingMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_AgentWarrantsIssuedInConnectionWithMay2020OfferingMember" xlink:label="poai_AgentWarrantsIssuedInConnectionWithMay2020OfferingMember" xlink:type="locator"/>
    <link:label xlink:label="poai_AgentWarrantsIssuedInConnectionWithMay2020OfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Agent Warrants Issued In connection With May 2020 Offering [Member]</link:label>
    <link:label xlink:label="poai_AgentWarrantsIssuedInConnectionWithMay2020OfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents agent warrants issued in connection with May 2020 offering.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_AgentWarrantsIssuedInConnectionWithMay2020OfferingMember" xlink:to="poai_AgentWarrantsIssuedInConnectionWithMay2020OfferingMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability" xlink:label="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative instrument recognized for May 2020 Warrants</link:label>
    <link:label xlink:label="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Embedded Derivative, Fair Value of Embedded Derivative Liability</link:label>
    <link:label xlink:label="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability-label" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Derivative liability balance</link:label>
    <link:label xlink:label="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability-label" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Derivative liability balance</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability" xlink:to="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodValueInducementToEquityLine" xlink:label="poai_StockIssuedDuringPeriodValueInducementToEquityLine" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodValueInducementToEquityLine-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares issued pursuant to Equity Line</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodValueInducementToEquityLine-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Value of stock issued for the inducement to equity line.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodValueInducementToEquityLine" xlink:to="poai_StockIssuedDuringPeriodValueInducementToEquityLine-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodSharesInducementToEquityLine" xlink:label="poai_StockIssuedDuringPeriodSharesInducementToEquityLine" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesInducementToEquityLine-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares issued pursuant to Equity Line (in shares)</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesInducementToEquityLine-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The number of shares issued during period for the inducement to equity line.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodSharesInducementToEquityLine" xlink:to="poai_StockIssuedDuringPeriodSharesInducementToEquityLine-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="us-gaap_ResearchAndDevelopmentExpense" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ResearchAndDevelopmentExpense-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ResearchAndDevelopmentExpense</link:label>
    <link:label xlink:label="us-gaap_ResearchAndDevelopmentExpense-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Research and Development Expense, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ResearchAndDevelopmentExpense" xlink:to="us-gaap_ResearchAndDevelopmentExpense-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_NumberOfWarrantsIssuedToEachInvestorPerTwoSharesOfStockPurchased" xlink:label="poai_NumberOfWarrantsIssuedToEachInvestorPerTwoSharesOfStockPurchased" xlink:type="locator"/>
    <link:label xlink:label="poai_NumberOfWarrantsIssuedToEachInvestorPerTwoSharesOfStockPurchased-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_NumberOfWarrantsIssuedToEachInvestorPerTwoSharesOfStockPurchased</link:label>
    <link:label xlink:label="poai_NumberOfWarrantsIssuedToEachInvestorPerTwoSharesOfStockPurchased-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of Warrants Issued to Each Investor, Per Two Shares of Stock Purchased (in shares)</link:label>
    <link:label xlink:label="poai_NumberOfWarrantsIssuedToEachInvestorPerTwoSharesOfStockPurchased-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The number of warrants issued to each investor, per two shares of stock purchased.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_NumberOfWarrantsIssuedToEachInvestorPerTwoSharesOfStockPurchased" xlink:to="poai_NumberOfWarrantsIssuedToEachInvestorPerTwoSharesOfStockPurchased-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accumulated Deficit</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_RegisteredDirectOfferingsMember" xlink:label="poai_RegisteredDirectOfferingsMember" xlink:type="locator"/>
    <link:label xlink:label="poai_RegisteredDirectOfferingsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Registered Direct Offerings [Member]</link:label>
    <link:label xlink:label="poai_RegisteredDirectOfferingsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to registered direct offerings.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_RegisteredDirectOfferingsMember" xlink:to="poai_RegisteredDirectOfferingsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_DrschwartzNotesMember" xlink:label="poai_DrschwartzNotesMember" xlink:type="locator"/>
    <link:label xlink:label="poai_DrschwartzNotesMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">DrSchwartz Notes [Member]</link:label>
    <link:label xlink:label="poai_DrschwartzNotesMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents DrSchwartz Notes.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_DrschwartzNotesMember" xlink:to="poai_DrschwartzNotesMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShortTermDebtTextBlock" xlink:label="us-gaap_ScheduleOfShortTermDebtTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfShortTermDebtTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Short-term Debt [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShortTermDebtTextBlock" xlink:to="us-gaap_ScheduleOfShortTermDebtTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PaymentsForPenalties" xlink:label="poai_PaymentsForPenalties" xlink:type="locator"/>
    <link:label xlink:label="poai_PaymentsForPenalties-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_PaymentsForPenalties</link:label>
    <link:label xlink:label="poai_PaymentsForPenalties-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Payments for Penalties</link:label>
    <link:label xlink:label="poai_PaymentsForPenalties-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Payment penalties</link:label>
    <link:label xlink:label="poai_PaymentsForPenalties-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The amount of payments for penalties.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PaymentsForPenalties" xlink:to="poai_PaymentsForPenalties-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_IndefinitelivedIntangibleAssetsExcludingGoodwillNet" xlink:label="poai_IndefinitelivedIntangibleAssetsExcludingGoodwillNet" xlink:type="locator"/>
    <link:label xlink:label="poai_IndefinitelivedIntangibleAssetsExcludingGoodwillNet-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Tradename</link:label>
    <link:label xlink:label="poai_IndefinitelivedIntangibleAssetsExcludingGoodwillNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_IndefinitelivedIntangibleAssetsExcludingGoodwillNet</link:label>
    <link:label xlink:label="poai_IndefinitelivedIntangibleAssetsExcludingGoodwillNet-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit, net of impairment.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_IndefinitelivedIntangibleAssetsExcludingGoodwillNet" xlink:to="poai_IndefinitelivedIntangibleAssetsExcludingGoodwillNet-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MeasurementInputDiscountRateMember" xlink:label="us-gaap_MeasurementInputDiscountRateMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_MeasurementInputDiscountRateMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Measurement Input, Discount Rate [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputDiscountRateMember" xlink:to="us-gaap_MeasurementInputDiscountRateMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SolubleBiodtechOfficesInBirminghamAlabamaMember" xlink:label="poai_SolubleBiodtechOfficesInBirminghamAlabamaMember" xlink:type="locator"/>
    <link:label xlink:label="poai_SolubleBiodtechOfficesInBirminghamAlabamaMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Soluble Biodtech Offices in Birmingham, Alabama [Member]</link:label>
    <link:label xlink:label="poai_SolubleBiodtechOfficesInBirminghamAlabamaMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to Soluble Biodtech offices located in Birmingham, Alabama.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SolubleBiodtechOfficesInBirminghamAlabamaMember" xlink:to="poai_SolubleBiodtechOfficesInBirminghamAlabamaMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_InvestorWarrantsMember" xlink:label="poai_InvestorWarrantsMember" xlink:type="locator"/>
    <link:label xlink:label="poai_InvestorWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Investor Warrants [Member]</link:label>
    <link:label xlink:label="poai_InvestorWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to investor warrants.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_InvestorWarrantsMember" xlink:to="poai_InvestorWarrantsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ZPREDICTAMember" xlink:label="poai_ZPREDICTAMember" xlink:type="locator"/>
    <link:label xlink:label="poai_ZPREDICTAMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">zPREDICTA [Member]</link:label>
    <link:label xlink:label="poai_ZPREDICTAMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents zPREDICTA business segment.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ZPREDICTAMember" xlink:to="poai_ZPREDICTAMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtDisclosureTextBlock" xlink:label="us-gaap_DebtDisclosureTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Disclosure [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtDisclosureTextBlock" xlink:to="us-gaap_DebtDisclosureTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SalesOfStockTableTextBlock" xlink:label="poai_SalesOfStockTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="poai_SalesOfStockTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sales of Stock [Table Text Block]</link:label>
    <link:label xlink:label="poai_SalesOfStockTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Tabular disclosure for sales and offerings of stock, including private placements.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SalesOfStockTableTextBlock" xlink:to="poai_SalesOfStockTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_January122021RegisteredDirectOfferingMember" xlink:label="poai_January122021RegisteredDirectOfferingMember" xlink:type="locator"/>
    <link:label xlink:label="poai_January122021RegisteredDirectOfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">January 12, 2021 Registered Direct Offering [Member]</link:label>
    <link:label xlink:label="poai_January122021RegisteredDirectOfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to the January 12, 2021 registered direct offering.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_January122021RegisteredDirectOfferingMember" xlink:to="poai_January122021RegisteredDirectOfferingMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_January212021RegisteredDirectOfferingMember" xlink:label="poai_January212021RegisteredDirectOfferingMember" xlink:type="locator"/>
    <link:label xlink:label="poai_January212021RegisteredDirectOfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">January 21, 2021 Registered Direct Offering [Member]</link:label>
    <link:label xlink:label="poai_January212021RegisteredDirectOfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to the January 21, 2021 registered direct offering.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_January212021RegisteredDirectOfferingMember" xlink:to="poai_January212021RegisteredDirectOfferingMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_June162021RegisteredDirectOfferingMember" xlink:label="poai_June162021RegisteredDirectOfferingMember" xlink:type="locator"/>
    <link:label xlink:label="poai_June162021RegisteredDirectOfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">June 16, 2021 Registered Direct Offering [Member]</link:label>
    <link:label xlink:label="poai_June162021RegisteredDirectOfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information regarding the June 2021 registered direct offering.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_June162021RegisteredDirectOfferingMember" xlink:to="poai_June162021RegisteredDirectOfferingMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SaleOfStockAgentPlacementFeePercentOfGrossProceeds" xlink:label="poai_SaleOfStockAgentPlacementFeePercentOfGrossProceeds" xlink:type="locator"/>
    <link:label xlink:label="poai_SaleOfStockAgentPlacementFeePercentOfGrossProceeds-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_SaleOfStockAgentPlacementFeePercentOfGrossProceeds</link:label>
    <link:label xlink:label="poai_SaleOfStockAgentPlacementFeePercentOfGrossProceeds-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Sale of Stock, Agent Placement Fee, Percent of Gross Proceeds</link:label>
    <link:label xlink:label="poai_SaleOfStockAgentPlacementFeePercentOfGrossProceeds-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The percent of gross proceeds for an agent placement fee in the sale of stock.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SaleOfStockAgentPlacementFeePercentOfGrossProceeds" xlink:to="poai_SaleOfStockAgentPlacementFeePercentOfGrossProceeds-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_MeasurementInputRiskPremiumMember" xlink:label="poai_MeasurementInputRiskPremiumMember" xlink:type="locator"/>
    <link:label xlink:label="poai_MeasurementInputRiskPremiumMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Measurement Input, Risk Premium [Member]</link:label>
    <link:label xlink:label="poai_MeasurementInputRiskPremiumMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the risk premium used for risks related to the term of the forecasts.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_MeasurementInputRiskPremiumMember" xlink:to="poai_MeasurementInputRiskPremiumMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MeasurementInputPriceVolatilityMember" xlink:label="us-gaap_MeasurementInputPriceVolatilityMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_MeasurementInputPriceVolatilityMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Measurement Input, Price Volatility [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputPriceVolatilityMember" xlink:to="us-gaap_MeasurementInputPriceVolatilityMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SaleOfStockManagementFeePercentOfGrossProceeds" xlink:label="poai_SaleOfStockManagementFeePercentOfGrossProceeds" xlink:type="locator"/>
    <link:label xlink:label="poai_SaleOfStockManagementFeePercentOfGrossProceeds-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_SaleOfStockManagementFeePercentOfGrossProceeds</link:label>
    <link:label xlink:label="poai_SaleOfStockManagementFeePercentOfGrossProceeds-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Sale of Stock, Management Fee, Percent of Gross Proceeds</link:label>
    <link:label xlink:label="poai_SaleOfStockManagementFeePercentOfGrossProceeds-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The percent of gross proceeds for a management fee in a sale of stock.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SaleOfStockManagementFeePercentOfGrossProceeds" xlink:to="poai_SaleOfStockManagementFeePercentOfGrossProceeds-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_MeasurementInputExpectedCashFlowTermMember" xlink:label="poai_MeasurementInputExpectedCashFlowTermMember" xlink:type="locator"/>
    <link:label xlink:label="poai_MeasurementInputExpectedCashFlowTermMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Measurement Input, Expected Cash Flow Term [Member]</link:label>
    <link:label xlink:label="poai_MeasurementInputExpectedCashFlowTermMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the expected cash flow period.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_MeasurementInputExpectedCashFlowTermMember" xlink:to="poai_MeasurementInputExpectedCashFlowTermMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Changes in assets and liabilities:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SaleOfStockPlacementAgentWarrantsAssignedNumberOfSecuritiesCalledByWarrantsPercentOfSharesSold" xlink:label="poai_SaleOfStockPlacementAgentWarrantsAssignedNumberOfSecuritiesCalledByWarrantsPercentOfSharesSold" xlink:type="locator"/>
    <link:label xlink:label="poai_SaleOfStockPlacementAgentWarrantsAssignedNumberOfSecuritiesCalledByWarrantsPercentOfSharesSold-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_SaleOfStockPlacementAgentWarrantsAssignedNumberOfSecuritiesCalledByWarrantsPercentOfSharesSold</link:label>
    <link:label xlink:label="poai_SaleOfStockPlacementAgentWarrantsAssignedNumberOfSecuritiesCalledByWarrantsPercentOfSharesSold-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Sale of Stock, Placement Agent, Warrants Assigned, Number of Securities Called by Warrants, Percent of Shares Sold</link:label>
    <link:label xlink:label="poai_SaleOfStockPlacementAgentWarrantsAssignedNumberOfSecuritiesCalledByWarrantsPercentOfSharesSold-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The percent of shares sold that warrants assigned to placement agents may be called by the warrants, under a sale of stock.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SaleOfStockPlacementAgentWarrantsAssignedNumberOfSecuritiesCalledByWarrantsPercentOfSharesSold" xlink:to="poai_SaleOfStockPlacementAgentWarrantsAssignedNumberOfSecuritiesCalledByWarrantsPercentOfSharesSold-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ReportingUnitMeasurementInput" xlink:label="poai_ReportingUnitMeasurementInput" xlink:type="locator"/>
    <link:label xlink:label="poai_ReportingUnitMeasurementInput-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_ReportingUnitMeasurementInput</link:label>
    <link:label xlink:label="poai_ReportingUnitMeasurementInput-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Reporting Unit Measurement Input</link:label>
    <link:label xlink:label="poai_ReportingUnitMeasurementInput-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The measurement input for reporting unit.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ReportingUnitMeasurementInput" xlink:to="poai_ReportingUnitMeasurementInput-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsPercentOfStockPrice" xlink:label="poai_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsPercentOfStockPrice" xlink:type="locator"/>
    <link:label xlink:label="poai_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsPercentOfStockPrice-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsPercentOfStockPrice</link:label>
    <link:label xlink:label="poai_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsPercentOfStockPrice-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class of Warrant or Right, Exercise Price of Warrants or Rights, Percent of Stock Price</link:label>
    <link:label xlink:label="poai_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsPercentOfStockPrice-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Exercise price per share or per unit of warrants or rights outstanding as a percentage of stock price.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsPercentOfStockPrice" xlink:to="poai_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsPercentOfStockPrice-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MeasurementInputRiskFreeInterestRateMember" xlink:label="us-gaap_MeasurementInputRiskFreeInterestRateMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_MeasurementInputRiskFreeInterestRateMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Measurement Input, Risk Free Interest Rate [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputRiskFreeInterestRateMember" xlink:to="us-gaap_MeasurementInputRiskFreeInterestRateMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_TumorgenesisOfficesInSalemMassachusettsMember" xlink:label="poai_TumorgenesisOfficesInSalemMassachusettsMember" xlink:type="locator"/>
    <link:label xlink:label="poai_TumorgenesisOfficesInSalemMassachusettsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">TumorGenesis Offices In Salem Massachusetts [Member]</link:label>
    <link:label xlink:label="poai_TumorgenesisOfficesInSalemMassachusettsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents TumorGenesis offices located in Salem, Massachusetts.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_TumorgenesisOfficesInSalemMassachusettsMember" xlink:to="poai_TumorgenesisOfficesInSalemMassachusettsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_DebtExtinguishmentCosts" xlink:label="poai_DebtExtinguishmentCosts" xlink:type="locator"/>
    <link:label xlink:label="poai_DebtExtinguishmentCosts-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt extinguishment costs</link:label>
    <link:label xlink:label="poai_DebtExtinguishmentCosts-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Loss on early extinguishment of debt</link:label>
    <link:label xlink:label="poai_DebtExtinguishmentCosts-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The amount of expenses associated with the extinguishment of debt prior to maturity.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_DebtExtinguishmentCosts" xlink:to="poai_DebtExtinguishmentCosts-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExpirationsWeightedAverageGrantDateFairValue" xlink:label="poai_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExpirationsWeightedAverageGrantDateFairValue" xlink:type="locator"/>
    <link:label xlink:label="poai_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExpirationsWeightedAverageGrantDateFairValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExpirationsWeightedAverageGrantDateFairValue</link:label>
    <link:label xlink:label="poai_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExpirationsWeightedAverageGrantDateFairValue-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Expired (in dollars per share)</link:label>
    <link:label xlink:label="poai_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExpirationsWeightedAverageGrantDateFairValue-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were expired.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExpirationsWeightedAverageGrantDateFairValue" xlink:to="poai_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExpirationsWeightedAverageGrantDateFairValue-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisclosureTextBlockAbstract" xlink:label="us-gaap_DisclosureTextBlockAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DisclosureTextBlockAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DisclosureTextBlockAbstract</link:label>
    <link:label xlink:label="us-gaap_DisclosureTextBlockAbstract-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Notes to Financial Statements</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisclosureTextBlockAbstract" xlink:to="us-gaap_DisclosureTextBlockAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PromissoryNote20202Member" xlink:label="poai_PromissoryNote20202Member" xlink:type="locator"/>
    <link:label xlink:label="poai_PromissoryNote20202Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Promissory Note 2020 2 [Member]</link:label>
    <link:label xlink:label="poai_PromissoryNote20202Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to the promissory note 2020.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PromissoryNote20202Member" xlink:to="poai_PromissoryNote20202Member-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative Instruments and Hedging Activities Disclosure [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock" xlink:to="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoryDisclosureTextBlock" xlink:label="us-gaap_InventoryDisclosureTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_InventoryDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Inventory Disclosure [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryDisclosureTextBlock" xlink:to="us-gaap_InventoryDisclosureTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="us-gaap_SubsequentEventMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SubsequentEventMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Event [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventMember" xlink:to="us-gaap_SubsequentEventMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_January262021RegisteredDirectOfferingMember" xlink:label="poai_January262021RegisteredDirectOfferingMember" xlink:type="locator"/>
    <link:label xlink:label="poai_January262021RegisteredDirectOfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">January 26, 2021 Registered Direct Offering [Member]</link:label>
    <link:label xlink:label="poai_January262021RegisteredDirectOfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to the January 26, 2021 registered direct offering.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_January262021RegisteredDirectOfferingMember" xlink:to="poai_January262021RegisteredDirectOfferingMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lease Liability, long-term portion</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MeasurementInputExpectedDividendRateMember" xlink:label="us-gaap_MeasurementInputExpectedDividendRateMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_MeasurementInputExpectedDividendRateMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Measurement Input, Expected Dividend Rate [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputExpectedDividendRateMember" xlink:to="us-gaap_MeasurementInputExpectedDividendRateMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_OtherFinitelivedIntangibleAssetsMember" xlink:label="poai_OtherFinitelivedIntangibleAssetsMember" xlink:type="locator"/>
    <link:label xlink:label="poai_OtherFinitelivedIntangibleAssetsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Finite-lived Intangible Assets [Member]</link:label>
    <link:label xlink:label="poai_OtherFinitelivedIntangibleAssetsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents other finite-lived intangible assets.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_OtherFinitelivedIntangibleAssetsMember" xlink:to="poai_OtherFinitelivedIntangibleAssetsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfInventoryCurrentTableTextBlock" xlink:label="us-gaap_ScheduleOfInventoryCurrentTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfInventoryCurrentTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Inventory, Current [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfInventoryCurrentTableTextBlock" xlink:to="us-gaap_ScheduleOfInventoryCurrentTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_February162021RegisteredDirectOfferingMember" xlink:label="poai_February162021RegisteredDirectOfferingMember" xlink:type="locator"/>
    <link:label xlink:label="poai_February162021RegisteredDirectOfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">February 16, 2021 Registered Direct Offering [Member]</link:label>
    <link:label xlink:label="poai_February162021RegisteredDirectOfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to the February 16, 2021 registered direct offering.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_February162021RegisteredDirectOfferingMember" xlink:to="poai_February162021RegisteredDirectOfferingMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MeasurementInputExpectedTermMember" xlink:label="us-gaap_MeasurementInputExpectedTermMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_MeasurementInputExpectedTermMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Measurement Input, Expected Term [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputExpectedTermMember" xlink:to="us-gaap_MeasurementInputExpectedTermMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_OtherExpensePolicyPolicyTextBlock" xlink:label="poai_OtherExpensePolicyPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="poai_OtherExpensePolicyPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Expense Policy [Policy Text Block]</link:label>
    <link:label xlink:label="poai_OtherExpensePolicyPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Disclosure of accounting policy for other expense.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_OtherExpensePolicyPolicyTextBlock" xlink:to="poai_OtherExpensePolicyPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_Febuary232021PrivatePlacementMember" xlink:label="poai_Febuary232021PrivatePlacementMember" xlink:type="locator"/>
    <link:label xlink:label="poai_Febuary232021PrivatePlacementMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Febuary 23, 2021 Private Placement [Member]</link:label>
    <link:label xlink:label="poai_Febuary232021PrivatePlacementMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to the February 23, 2021 private placement.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_Febuary232021PrivatePlacementMember" xlink:to="poai_Febuary232021PrivatePlacementMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MeasurementInputLongTermRevenueGrowthRateMember" xlink:label="us-gaap_MeasurementInputLongTermRevenueGrowthRateMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_MeasurementInputLongTermRevenueGrowthRateMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Measurement Input, Long-term Revenue Growth Rate [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputLongTermRevenueGrowthRateMember" xlink:to="us-gaap_MeasurementInputLongTermRevenueGrowthRateMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ZPREDICTAOfficesInSanJoseCaliforniaMember" xlink:label="poai_ZPREDICTAOfficesInSanJoseCaliforniaMember" xlink:type="locator"/>
    <link:label xlink:label="poai_ZPREDICTAOfficesInSanJoseCaliforniaMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">zPREDICTA Offices in San Jose California [Member]</link:label>
    <link:label xlink:label="poai_ZPREDICTAOfficesInSanJoseCaliforniaMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents zPREDICTA offices located in San Jose, California.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ZPREDICTAOfficesInSanJoseCaliforniaMember" xlink:to="poai_ZPREDICTAOfficesInSanJoseCaliforniaMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseLiability" xlink:label="us-gaap_OperatingLeaseLiability" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingLeaseLiability-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Present value of lease liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiability" xlink:to="us-gaap_OperatingLeaseLiability-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="us-gaap_SubsequentEventTypeAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SubsequentEventTypeAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Event Type [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventTypeAxis" xlink:to="us-gaap_SubsequentEventTypeAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingLeaseLiabilityCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lease Liability &#8211; Net of Long-Term Portion</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityCurrent" xlink:to="us-gaap_OperatingLeaseLiabilityCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="us-gaap_SubsequentEventTypeDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SubsequentEventTypeDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Event Type [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventTypeDomain" xlink:to="us-gaap_SubsequentEventTypeDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:label="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Retirement Benefits [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:to="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockOptions2021Member" xlink:label="poai_StockOptions2021Member" xlink:type="locator"/>
    <link:label xlink:label="poai_StockOptions2021Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Options 2021 [Member]</link:label>
    <link:label xlink:label="poai_StockOptions2021Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to stock options in 2021.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockOptions2021Member" xlink:to="poai_StockOptions2021Member-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:label="us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IntangibleAssetsGrossExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Total, Gross Carrying Costs</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:to="us-gaap_IntangibleAssetsGrossExcludingGoodwill-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsequentEventsTextBlock" xlink:label="us-gaap_SubsequentEventsTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SubsequentEventsTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Events [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventsTextBlock" xlink:to="us-gaap_SubsequentEventsTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_HelomicsOfficesLeaseAreaForOfficeSpaceMember" xlink:label="poai_HelomicsOfficesLeaseAreaForOfficeSpaceMember" xlink:type="locator"/>
    <link:label xlink:label="poai_HelomicsOfficesLeaseAreaForOfficeSpaceMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Helomics Offices, Lease Area for Office Space [Member]</link:label>
    <link:label xlink:label="poai_HelomicsOfficesLeaseAreaForOfficeSpaceMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to Helomics offices leased area for office space.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_HelomicsOfficesLeaseAreaForOfficeSpaceMember" xlink:to="poai_HelomicsOfficesLeaseAreaForOfficeSpaceMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingLeaseRightOfUseAsset-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lease Right-of-Use Assets</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseRightOfUseAsset" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_HelomicsOfficesLeaseAreaForLaboratoryMember" xlink:label="poai_HelomicsOfficesLeaseAreaForLaboratoryMember" xlink:type="locator"/>
    <link:label xlink:label="poai_HelomicsOfficesLeaseAreaForLaboratoryMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Helomics Offices, Lease Area for Laboratory [Member]</link:label>
    <link:label xlink:label="poai_HelomicsOfficesLeaseAreaForLaboratoryMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to Helomics offices leased area for laboratory.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_HelomicsOfficesLeaseAreaForLaboratoryMember" xlink:to="poai_HelomicsOfficesLeaseAreaForLaboratoryMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue</link:label>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total lease payments</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_DrSchwartzNotesWarrantsMember" xlink:label="poai_DrSchwartzNotesWarrantsMember" xlink:type="locator"/>
    <link:label xlink:label="poai_DrSchwartzNotesWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Dr. Schwartz Notes Warrants [Member]</link:label>
    <link:label xlink:label="poai_DrSchwartzNotesWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the warrants issued with Dr. Schwartz Notes.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_DrSchwartzNotesWarrantsMember" xlink:to="poai_DrSchwartzNotesWarrantsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Less interest</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PenaltiesAccrued" xlink:label="poai_PenaltiesAccrued" xlink:type="locator"/>
    <link:label xlink:label="poai_PenaltiesAccrued-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_PenaltiesAccrued</link:label>
    <link:label xlink:label="poai_PenaltiesAccrued-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Penalties Accrued</link:label>
    <link:label xlink:label="poai_PenaltiesAccrued-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The amount of liabilities for penalties.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PenaltiesAccrued" xlink:to="poai_PenaltiesAccrued-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MeasurementInputTypeAxis" xlink:label="us-gaap_MeasurementInputTypeAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_MeasurementInputTypeAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Measurement Input Type [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputTypeAxis" xlink:to="us-gaap_MeasurementInputTypeAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_EmbeddedDerivativeNoLongerBifurcatedAmountReclassifiedToStockholdersEquityOnExercise" xlink:label="poai_EmbeddedDerivativeNoLongerBifurcatedAmountReclassifiedToStockholdersEquityOnExercise" xlink:type="locator"/>
    <link:label xlink:label="poai_EmbeddedDerivativeNoLongerBifurcatedAmountReclassifiedToStockholdersEquityOnExercise-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_EmbeddedDerivativeNoLongerBifurcatedAmountReclassifiedToStockholdersEquityOnExercise</link:label>
    <link:label xlink:label="poai_EmbeddedDerivativeNoLongerBifurcatedAmountReclassifiedToStockholdersEquityOnExercise-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Reclassification of Warrant liabilities to Equity on exercise</link:label>
    <link:label xlink:label="poai_EmbeddedDerivativeNoLongerBifurcatedAmountReclassifiedToStockholdersEquityOnExercise-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The amount of embedded derivative no longer bifurcated reclassified to stockholders equity on exercise.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_EmbeddedDerivativeNoLongerBifurcatedAmountReclassifiedToStockholdersEquityOnExercise" xlink:to="poai_EmbeddedDerivativeNoLongerBifurcatedAmountReclassifiedToStockholdersEquityOnExercise-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree</link:label>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2024</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive</link:label>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Thereafter</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodSharesExtensionOfNotesPayable" xlink:label="poai_StockIssuedDuringPeriodSharesExtensionOfNotesPayable" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesExtensionOfNotesPayable-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_StockIssuedDuringPeriodSharesExtensionOfNotesPayable</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesExtensionOfNotesPayable-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Stock Issued During Period, Shares, Extension of Notes Payable (in shares)</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesExtensionOfNotesPayable-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The number of shares issued for the extension of notes payable.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodSharesExtensionOfNotesPayable" xlink:to="poai_StockIssuedDuringPeriodSharesExtensionOfNotesPayable-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MeasurementInputTypeDomain" xlink:label="us-gaap_MeasurementInputTypeDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_MeasurementInputTypeDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Measurement Input Type [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputTypeDomain" xlink:to="us-gaap_MeasurementInputTypeDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour</link:label>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2025</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_AccumulatedImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill" xlink:label="poai_AccumulatedImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill" xlink:type="locator"/>
    <link:label xlink:label="poai_AccumulatedImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_AccumulatedImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill</link:label>
    <link:label xlink:label="poai_AccumulatedImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Tradename</link:label>
    <link:label xlink:label="poai_AccumulatedImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The amount of accumulated impairment of intangible assets that are indefinite-lived, excluding goodwill.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_AccumulatedImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill" xlink:to="poai_AccumulatedImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_CorporateOfficeMinnesotaUsedForOfficeSpaceMember" xlink:label="poai_CorporateOfficeMinnesotaUsedForOfficeSpaceMember" xlink:type="locator"/>
    <link:label xlink:label="poai_CorporateOfficeMinnesotaUsedForOfficeSpaceMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Corporate Office, Minnesota, Used for Office Space [Member]</link:label>
    <link:label xlink:label="poai_CorporateOfficeMinnesotaUsedForOfficeSpaceMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to the corporate office in Minnesota used for office space.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_CorporateOfficeMinnesotaUsedForOfficeSpaceMember" xlink:to="poai_CorporateOfficeMinnesotaUsedForOfficeSpaceMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SeriesEPreferredStockConversionsMember" xlink:label="poai_SeriesEPreferredStockConversionsMember" xlink:type="locator"/>
    <link:label xlink:label="poai_SeriesEPreferredStockConversionsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Series E Preferred Stock Conversions [Member]</link:label>
    <link:label xlink:label="poai_SeriesEPreferredStockConversionsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the series E preferred stock conversions.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SeriesEPreferredStockConversionsMember" xlink:to="poai_SeriesEPreferredStockConversionsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_CorporateOfficeMinnesotaUsedForManufacturingMember" xlink:label="poai_CorporateOfficeMinnesotaUsedForManufacturingMember" xlink:type="locator"/>
    <link:label xlink:label="poai_CorporateOfficeMinnesotaUsedForManufacturingMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Corporate Office, Minnesota, Used for Manufacturing [Member]</link:label>
    <link:label xlink:label="poai_CorporateOfficeMinnesotaUsedForManufacturingMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The corporate office in Minnesota used for manufacturing.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_CorporateOfficeMinnesotaUsedForManufacturingMember" xlink:to="poai_CorporateOfficeMinnesotaUsedForManufacturingMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:label="us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FairValueMeasurementPolicyPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value Measurement, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:to="us-gaap_FairValueMeasurementPolicyPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo</link:label>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2023</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree</link:label>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2024</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths</link:label>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2022</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour</link:label>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2025</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo</link:label>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2023</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive</link:label>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2026</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:label="us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:to="us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_Warrants2021Member" xlink:label="poai_Warrants2021Member" xlink:type="locator"/>
    <link:label xlink:label="poai_Warrants2021Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants 2021 [Member]</link:label>
    <link:label xlink:label="poai_Warrants2021Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information regarding the 2021 warrants.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_Warrants2021Member" xlink:to="poai_Warrants2021Member-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths</link:label>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2022</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PriceOfWarrant" xlink:label="poai_PriceOfWarrant" xlink:type="locator"/>
    <link:label xlink:label="poai_PriceOfWarrant-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_PriceOfWarrant</link:label>
    <link:label xlink:label="poai_PriceOfWarrant-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Price of Warrant (in dollars per share)</link:label>
    <link:label xlink:label="poai_PriceOfWarrant-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The price of warrant.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PriceOfWarrant" xlink:to="poai_PriceOfWarrant-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PatentsAndTrademarksMember" xlink:label="poai_PatentsAndTrademarksMember" xlink:type="locator"/>
    <link:label xlink:label="poai_PatentsAndTrademarksMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Patents and Trademarks [Member]</link:label>
    <link:label xlink:label="poai_PatentsAndTrademarksMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents patents and trademarks.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PatentsAndTrademarksMember" xlink:to="poai_PatentsAndTrademarksMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SeriesBConvertiblePreferredStockMember" xlink:label="poai_SeriesBConvertiblePreferredStockMember" xlink:type="locator"/>
    <link:label xlink:label="poai_SeriesBConvertiblePreferredStockMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Series B Convertible Preferred Stock [Member]</link:label>
    <link:label xlink:label="poai_SeriesBConvertiblePreferredStockMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Outstanding nonredeemable series B preferred stock that is convertible and may be exchanged into common shares or other types of securities at the owner's option. Classified within stockholders' equity if nonredeemable or redeemable solely at the option of the issuer. Classified within temporary equity if redemption is outside the control of the issuer.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SeriesBConvertiblePreferredStockMember" xlink:to="poai_SeriesBConvertiblePreferredStockMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_WarrantsIssuedWithPrivatePlacementMember" xlink:label="poai_WarrantsIssuedWithPrivatePlacementMember" xlink:type="locator"/>
    <link:label xlink:label="poai_WarrantsIssuedWithPrivatePlacementMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants issued with Private Placement [Member]</link:label>
    <link:label xlink:label="poai_WarrantsIssuedWithPrivatePlacementMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the warrants issued with private placement.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantsIssuedWithPrivatePlacementMember" xlink:to="poai_WarrantsIssuedWithPrivatePlacementMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAdjustmentOfWarrants" xlink:label="us-gaap_FairValueAdjustmentOfWarrants" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FairValueAdjustmentOfWarrants-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Gain on valuation of equity-linked instruments</link:label>
    <link:label xlink:label="us-gaap_FairValueAdjustmentOfWarrants-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value Adjustment of Warrants</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueAdjustmentOfWarrants" xlink:to="us-gaap_FairValueAdjustmentOfWarrants-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodSharesWarrantsExercised" xlink:label="poai_StockIssuedDuringPeriodSharesWarrantsExercised" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesWarrantsExercised-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Issuance of shares from prefunded warrant exercises (in shares)</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesWarrantsExercised-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Number of shares issued as a result of the exercise of warrants.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodSharesWarrantsExercised" xlink:to="poai_StockIssuedDuringPeriodSharesWarrantsExercised-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodValueIssuedForServicesAndOtherAdjustments" xlink:label="poai_StockIssuedDuringPeriodValueIssuedForServicesAndOtherAdjustments" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodValueIssuedForServicesAndOtherAdjustments-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share issuance to consultant and other</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodValueIssuedForServicesAndOtherAdjustments-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The values shares issued for services and other adjustments to equity.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodValueIssuedForServicesAndOtherAdjustments" xlink:to="poai_StockIssuedDuringPeriodValueIssuedForServicesAndOtherAdjustments-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodValueWarrantsExercised" xlink:label="poai_StockIssuedDuringPeriodValueWarrantsExercised" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodValueWarrantsExercised-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Issuance of shares from prefunded warrant exercises</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodValueWarrantsExercised-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Value of stock issued as a result of the exercise of warrants.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodValueWarrantsExercised" xlink:to="poai_StockIssuedDuringPeriodValueWarrantsExercised-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PrefundedWarrantMember" xlink:label="poai_PrefundedWarrantMember" xlink:type="locator"/>
    <link:label xlink:label="poai_PrefundedWarrantMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Prefunded Warrant [Member]</link:label>
    <link:label xlink:label="poai_PrefundedWarrantMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the prefunded warrant.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PrefundedWarrantMember" xlink:to="poai_PrefundedWarrantMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtConversionConvertedInstrumentAmount1" xlink:label="us-gaap_DebtConversionConvertedInstrumentAmount1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtConversionConvertedInstrumentAmount1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DebtConversionConvertedInstrumentAmount1</link:label>
    <link:label xlink:label="us-gaap_DebtConversionConvertedInstrumentAmount1-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Conversion, Converted Instrument, Amount</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtConversionConvertedInstrumentAmount1" xlink:to="us-gaap_DebtConversionConvertedInstrumentAmount1-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Operating Lease, Liability, Maturity [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="us-gaap_OtherAssetsNoncurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OtherAssetsNoncurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Long-Term Assets</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssetsNoncurrent" xlink:to="us-gaap_OtherAssetsNoncurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensation-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Vesting expense</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensation-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensation</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensation" xlink:to="us-gaap_ShareBasedCompensation-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeLeasesPolicyTextBlock" xlink:label="us-gaap_LesseeLeasesPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeLeasesPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Leases [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeLeasesPolicyTextBlock" xlink:to="us-gaap_LesseeLeasesPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtConversionConvertedInstrumentSharesIssued1" xlink:label="us-gaap_DebtConversionConvertedInstrumentSharesIssued1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtConversionConvertedInstrumentSharesIssued1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DebtConversionConvertedInstrumentSharesIssued1</link:label>
    <link:label xlink:label="us-gaap_DebtConversionConvertedInstrumentSharesIssued1-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Conversion, Converted Instrument, Shares Issued (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtConversionConvertedInstrumentSharesIssued1" xlink:to="us-gaap_DebtConversionConvertedInstrumentSharesIssued1-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_FiniteLivedIntangibleAssetUsefulLife</link:label>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Asset, Useful Life (Year)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:to="us-gaap_FiniteLivedIntangibleAssetUsefulLife-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_DevelopedTechnologyMember" xlink:label="poai_DevelopedTechnologyMember" xlink:type="locator"/>
    <link:label xlink:label="poai_DevelopedTechnologyMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Developed Technology [Member]</link:label>
    <link:label xlink:label="poai_DevelopedTechnologyMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents developed technology.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_DevelopedTechnologyMember" xlink:to="poai_DevelopedTechnologyMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtConversionOriginalDebtAmount1" xlink:label="us-gaap_DebtConversionOriginalDebtAmount1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtConversionOriginalDebtAmount1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DebtConversionOriginalDebtAmount1</link:label>
    <link:label xlink:label="us-gaap_DebtConversionOriginalDebtAmount1-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Conversion, Original Debt, Amount</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtConversionOriginalDebtAmount1" xlink:to="us-gaap_DebtConversionOriginalDebtAmount1-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtConversionByUniqueDescriptionAxis" xlink:label="us-gaap_DebtConversionByUniqueDescriptionAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtConversionByUniqueDescriptionAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Conversion Description [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtConversionByUniqueDescriptionAxis" xlink:to="us-gaap_DebtConversionByUniqueDescriptionAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtConversionNameDomain" xlink:label="us-gaap_DebtConversionNameDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtConversionNameDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Conversion, Name [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtConversionNameDomain" xlink:to="us-gaap_DebtConversionNameDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AmortizationOfDebtDiscountPremium" xlink:label="us-gaap_AmortizationOfDebtDiscountPremium" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AmortizationOfDebtDiscountPremium-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Amortization of debt discount</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfDebtDiscountPremium" xlink:to="us-gaap_AmortizationOfDebtDiscountPremium-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxPolicyTextBlock" xlink:label="us-gaap_IncomeTaxPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income Tax, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxPolicyTextBlock" xlink:to="us-gaap_IncomeTaxPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Finite-Lived Intangible Assets [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock" xlink:to="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseTermOfContract" xlink:label="us-gaap_LesseeOperatingLeaseTermOfContract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseTermOfContract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LesseeOperatingLeaseTermOfContract</link:label>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseTermOfContract-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Lessee, Operating Lease, Term of Contract (Year)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseTermOfContract" xlink:to="us-gaap_LesseeOperatingLeaseTermOfContract-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Research and Development Expense, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:to="us-gaap_ResearchAndDevelopmentExpensePolicy-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConversionOfStockAmountConverted1" xlink:label="us-gaap_ConversionOfStockAmountConverted1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ConversionOfStockAmountConverted1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred stock conversions</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConversionOfStockAmountConverted1" xlink:to="us-gaap_ConversionOfStockAmountConverted1-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Depreciation" xlink:label="us-gaap_Depreciation" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_Depreciation-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_Depreciation</link:label>
    <link:label xlink:label="us-gaap_Depreciation-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Depreciation, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Depreciation" xlink:to="us-gaap_Depreciation-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConversionOfStockSharesIssued1" xlink:label="us-gaap_ConversionOfStockSharesIssued1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ConversionOfStockSharesIssued1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ConversionOfStockSharesIssued1</link:label>
    <link:label xlink:label="us-gaap_ConversionOfStockSharesIssued1-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Conversion of Stock, Shares Issued (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConversionOfStockSharesIssued1" xlink:to="us-gaap_ConversionOfStockSharesIssued1-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityNoteStockSplitConversionRatio1" xlink:label="us-gaap_StockholdersEquityNoteStockSplitConversionRatio1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockholdersEquityNoteStockSplitConversionRatio1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_StockholdersEquityNoteStockSplitConversionRatio1</link:label>
    <link:label xlink:label="us-gaap_StockholdersEquityNoteStockSplitConversionRatio1-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Stockholders' Equity Note, Stock Split, Conversion Ratio</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityNoteStockSplitConversionRatio1" xlink:to="us-gaap_StockholdersEquityNoteStockSplitConversionRatio1-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="us-gaap_DepreciationDepletionAndAmortization" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DepreciationDepletionAndAmortization-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Depreciation and amortization</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationDepletionAndAmortization" xlink:to="us-gaap_DepreciationDepletionAndAmortization-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsAmendedPrice" xlink:label="poai_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsAmendedPrice" xlink:type="locator"/>
    <link:label xlink:label="poai_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsAmendedPrice-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsAmendedPrice</link:label>
    <link:label xlink:label="poai_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsAmendedPrice-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class of Warrant or Right, Exercise Price of Warrants or Rights, Amended Price (in dollars per share)</link:label>
    <link:label xlink:label="poai_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsAmendedPrice-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the amended exercise price for warrants or rights.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsAmendedPrice" xlink:to="poai_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsAmendedPrice-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IntangibleAssetsDisclosureTextBlock" xlink:label="us-gaap_IntangibleAssetsDisclosureTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IntangibleAssetsDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Intangible Assets Disclosure [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IntangibleAssetsDisclosureTextBlock" xlink:to="us-gaap_IntangibleAssetsDisclosureTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConversionOfStockSharesConverted1" xlink:label="us-gaap_ConversionOfStockSharesConverted1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ConversionOfStockSharesConverted1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ConversionOfStockSharesConverted1</link:label>
    <link:label xlink:label="us-gaap_ConversionOfStockSharesConverted1-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Conversion of Stock, Shares Converted (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConversionOfStockSharesConverted1" xlink:to="us-gaap_ConversionOfStockSharesConverted1-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SharesIssuedPricePerShare-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Shares issued, price per share (in dollars per share)</link:label>
    <link:label xlink:label="us-gaap_SharesIssuedPricePerShare-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares issued, price per share (in dollars per share)</link:label>
    <link:label xlink:label="us-gaap_SharesIssuedPricePerShare-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Shares Issued, Price Per Share (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesIssuedPricePerShare" xlink:to="us-gaap_SharesIssuedPricePerShare-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConversionOfStockByUniqueDescriptionAxis" xlink:label="us-gaap_ConversionOfStockByUniqueDescriptionAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ConversionOfStockByUniqueDescriptionAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Conversion Description [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConversionOfStockByUniqueDescriptionAxis" xlink:to="us-gaap_ConversionOfStockByUniqueDescriptionAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConversionOfStockNameDomain" xlink:label="us-gaap_ConversionOfStockNameDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ConversionOfStockNameDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Conversion of Stock, Name [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConversionOfStockNameDomain" xlink:to="us-gaap_ConversionOfStockNameDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AssetsCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_AssetsCurrent</link:label>
    <link:label xlink:label="us-gaap_AssetsCurrent-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total Current Assets</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AssetsCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stockholders' Equity Note Disclosure [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:to="us-gaap_StockholdersEquityNoteDisclosureTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_WarrantsIssuedPursuantTo2020ConvertibleDebt2Member" xlink:label="poai_WarrantsIssuedPursuantTo2020ConvertibleDebt2Member" xlink:type="locator"/>
    <link:label xlink:label="poai_WarrantsIssuedPursuantTo2020ConvertibleDebt2Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants Issued Pursuant to 2020 Convertible Debt 2 [Member]</link:label>
    <link:label xlink:label="poai_WarrantsIssuedPursuantTo2020ConvertibleDebt2Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents second warrant issued pursuant to 2020 convertible debt.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantsIssuedPursuantTo2020ConvertibleDebt2Member" xlink:to="poai_WarrantsIssuedPursuantTo2020ConvertibleDebt2Member-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill" xlink:label="us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Impairment</link:label>
    <link:label xlink:label="us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Loss on impairment intangibles</link:label>
    <link:label xlink:label="us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Impairment of Intangible Assets (Excluding Goodwill), Total</link:label>
    <link:label xlink:label="us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Impairment expense &#8211; intangibles</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill" xlink:to="us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CommonStockValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common Stock, $.01 par value, 200,000,000 and 100,000,000 authorized, 65,614,597 and 19,804,787 outstanding</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockValue" xlink:to="us-gaap_CommonStockValue-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodValueAccruedInterest" xlink:label="poai_StockIssuedDuringPeriodValueAccruedInterest" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodValueAccruedInterest-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_StockIssuedDuringPeriodValueAccruedInterest</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodValueAccruedInterest-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Shares issued pursuant to agreement with former CEO related to accrued interest</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodValueAccruedInterest-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The value of stock issued during the period for accrued interest.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodValueAccruedInterest" xlink:to="poai_StockIssuedDuringPeriodValueAccruedInterest-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIssuedDuringPeriodSharesAccruedInterest" xlink:label="poai_StockIssuedDuringPeriodSharesAccruedInterest" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesAccruedInterest-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_StockIssuedDuringPeriodSharesAccruedInterest</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesAccruedInterest-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Shares issued pursuant to agreement with former CEO related to accrued interest (in shares)</link:label>
    <link:label xlink:label="poai_StockIssuedDuringPeriodSharesAccruedInterest-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The number of shares issued during period for accrued interest.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIssuedDuringPeriodSharesAccruedInterest" xlink:to="poai_StockIssuedDuringPeriodSharesAccruedInterest-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Adjustments to reconcile net loss to net cash used in operating activities:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CommonStockSharesAuthorized-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common stock, shares authorized (in shares)</link:label>
    <link:label xlink:label="us-gaap_CommonStockSharesAuthorized-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Common Stock, Shares Authorized (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesAuthorized" xlink:to="us-gaap_CommonStockSharesAuthorized-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CommonStockParOrStatedValuePerShare-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common stock, par value (in dollars per share)</link:label>
    <link:label xlink:label="us-gaap_CommonStockParOrStatedValuePerShare-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Common Stock, Par or Stated Value Per Share (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockParOrStatedValuePerShare" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerPolicyTextBlock" xlink:label="us-gaap_RevenueFromContractWithCustomerPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RevenueFromContractWithCustomerPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue from Contract with Customer [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromContractWithCustomerPolicyTextBlock" xlink:to="us-gaap_RevenueFromContractWithCustomerPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_CommonStockCapitalSharesReservedForFutureIssuance</link:label>
    <link:label xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Common Stock, Capital Shares Reserved for Future Issuance (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:to="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsValuationAllowance</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Less: valuation allowance</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsValuationAllowance" xlink:to="us-gaap_DeferredTaxAssetsValuationAllowance-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember" xlink:label="srt_RangeMember" xlink:type="locator"/>
    <link:label xlink:label="srt_RangeMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statistical Measurement [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RangeMember" xlink:to="srt_RangeMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember" xlink:type="locator"/>
    <link:label xlink:label="srt_MaximumMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Maximum [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MaximumMember" xlink:to="srt_MaximumMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember" xlink:type="locator"/>
    <link:label xlink:label="srt_MinimumMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Minimum [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MinimumMember" xlink:to="srt_MinimumMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis" xlink:type="locator"/>
    <link:label xlink:label="srt_RangeAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statistical Measurement [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RangeAxis" xlink:to="srt_RangeAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PreferredStockValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Series B Convertible Preferred Stock, $.01 par value, 2,300,000 authorized, 79,246 and 79,246 shares outstanding</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockValue" xlink:to="us-gaap_PreferredStockValue-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsLiabilitiesNet</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:to="us-gaap_DeferredTaxAssetsLiabilitiesNet-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsIntangibleAssetsPolicy" xlink:label="us-gaap_GoodwillAndIntangibleAssetsIntangibleAssetsPolicy" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_GoodwillAndIntangibleAssetsIntangibleAssetsPolicy-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillAndIntangibleAssetsIntangibleAssetsPolicy" xlink:to="us-gaap_GoodwillAndIntangibleAssetsIntangibleAssetsPolicy-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="us-gaap_PreferredStockSharesIssued" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PreferredStockSharesIssued-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_PreferredStockSharesIssued</link:label>
    <link:label xlink:label="us-gaap_PreferredStockSharesIssued-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Preferred Stock, Shares Issued, Total (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesIssued" xlink:to="us-gaap_PreferredStockSharesIssued-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestPaidNet" xlink:label="us-gaap_InterestPaidNet" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_InterestPaidNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Interest paid on debt</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestPaidNet" xlink:to="us-gaap_InterestPaidNet-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment Disclosure [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_GainLossOnReceivablePreviouslyConsideredUncollectable" xlink:label="poai_GainLossOnReceivablePreviouslyConsideredUncollectable" xlink:type="locator"/>
    <link:label xlink:label="poai_GainLossOnReceivablePreviouslyConsideredUncollectable-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Gain on notes receivables associated with asset purchase</link:label>
    <link:label xlink:label="poai_GainLossOnReceivablePreviouslyConsideredUncollectable-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents gain (loss) on receivable previously consider uncollectable.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_GainLossOnReceivablePreviouslyConsideredUncollectable" xlink:to="poai_GainLossOnReceivablePreviouslyConsideredUncollectable-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_OfferingCostsPolicyTextBlock" xlink:label="poai_OfferingCostsPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="poai_OfferingCostsPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Offering Costs [Policy Text Block]</link:label>
    <link:label xlink:label="poai_OfferingCostsPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The accounting policy of offering costs related to securities financing transactions.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_OfferingCostsPolicyTextBlock" xlink:to="poai_OfferingCostsPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_AssetPurchaseSharesIssuedSharesEscrowDepositToBeReleasedUponSixMonthsAnniversaryOfClosing" xlink:label="poai_AssetPurchaseSharesIssuedSharesEscrowDepositToBeReleasedUponSixMonthsAnniversaryOfClosing" xlink:type="locator"/>
    <link:label xlink:label="poai_AssetPurchaseSharesIssuedSharesEscrowDepositToBeReleasedUponSixMonthsAnniversaryOfClosing-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_AssetPurchaseSharesIssuedSharesEscrowDepositToBeReleasedUponSixMonthsAnniversaryOfClosing</link:label>
    <link:label xlink:label="poai_AssetPurchaseSharesIssuedSharesEscrowDepositToBeReleasedUponSixMonthsAnniversaryOfClosing-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Asset Purchase Shares Issued Shares Escrow Deposit To Be Released Upon Six Months Anniversary Of Closing (in shares)</link:label>
    <link:label xlink:label="poai_AssetPurchaseSharesIssuedSharesEscrowDepositToBeReleasedUponSixMonthsAnniversaryOfClosing-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents asset purchases shares issued shares escrow deposit to be released upon six months anniversary of closing.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_AssetPurchaseSharesIssuedSharesEscrowDepositToBeReleasedUponSixMonthsAnniversaryOfClosing" xlink:to="poai_AssetPurchaseSharesIssuedSharesEscrowDepositToBeReleasedUponSixMonthsAnniversaryOfClosing-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsGross" xlink:label="us-gaap_DeferredTaxAssetsGross" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsGross-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsGross</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsGross-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total deferred tax assets</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsGross" xlink:to="us-gaap_DeferredTaxAssetsGross-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="us-gaap_PreferredStockSharesAuthorized" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PreferredStockSharesAuthorized-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred stock, shares authorized (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesAuthorized" xlink:to="us-gaap_PreferredStockSharesAuthorized-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy" xlink:label="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy" xlink:to="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_AssetPurchaseSharesIssuedSharesEscrowDepositToBeReleasedUponNineMonthsAnniversaryOfClosing" xlink:label="poai_AssetPurchaseSharesIssuedSharesEscrowDepositToBeReleasedUponNineMonthsAnniversaryOfClosing" xlink:type="locator"/>
    <link:label xlink:label="poai_AssetPurchaseSharesIssuedSharesEscrowDepositToBeReleasedUponNineMonthsAnniversaryOfClosing-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_AssetPurchaseSharesIssuedSharesEscrowDepositToBeReleasedUponNineMonthsAnniversaryOfClosing</link:label>
    <link:label xlink:label="poai_AssetPurchaseSharesIssuedSharesEscrowDepositToBeReleasedUponNineMonthsAnniversaryOfClosing-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Asset Purchase Shares Issued, Shares Escrow Deposit To Be Released Upon Nine Months Anniversary Of Closing (in shares)</link:label>
    <link:label xlink:label="poai_AssetPurchaseSharesIssuedSharesEscrowDepositToBeReleasedUponNineMonthsAnniversaryOfClosing-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents assets purchase shares issued shares escrow deposit to be released upon nine months anniversary of closing.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_AssetPurchaseSharesIssuedSharesEscrowDepositToBeReleasedUponNineMonthsAnniversaryOfClosing" xlink:to="poai_AssetPurchaseSharesIssuedSharesEscrowDepositToBeReleasedUponNineMonthsAnniversaryOfClosing-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredIncomeTaxLiabilities" xlink:label="us-gaap_DeferredIncomeTaxLiabilities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredIncomeTaxLiabilities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredIncomeTaxLiabilities</link:label>
    <link:label xlink:label="us-gaap_DeferredIncomeTaxLiabilities-label" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:type="resource" xml:lang="en-US">Total deferred tax liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxLiabilities" xlink:to="us-gaap_DeferredIncomeTaxLiabilities-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoryNet" xlink:label="us-gaap_InventoryNet" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_InventoryNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_InventoryNet</link:label>
    <link:label xlink:label="us-gaap_InventoryNet-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Inventories</link:label>
    <link:label xlink:label="us-gaap_InventoryNet-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryNet" xlink:to="us-gaap_InventoryNet-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred stock, par value (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockParOrStatedValuePerShare" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Revenue</link:label>
    <link:label xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:to="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ClassOfWarrantOrRightPurchasePricePerWarrant" xlink:label="poai_ClassOfWarrantOrRightPurchasePricePerWarrant" xlink:type="locator"/>
    <link:label xlink:label="poai_ClassOfWarrantOrRightPurchasePricePerWarrant-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_ClassOfWarrantOrRightPurchasePricePerWarrant</link:label>
    <link:label xlink:label="poai_ClassOfWarrantOrRightPurchasePricePerWarrant-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class Of Warrant Or Right, Purchase Price Per Warrant (in dollars per share)</link:label>
    <link:label xlink:label="poai_ClassOfWarrantOrRightPurchasePricePerWarrant-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents purchase price per warrant for class of warrant or right.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ClassOfWarrantOrRightPurchasePricePerWarrant" xlink:to="poai_ClassOfWarrantOrRightPurchasePricePerWarrant-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ProceedsFromIssuanceAndExerciseOfWarrants" xlink:label="poai_ProceedsFromIssuanceAndExerciseOfWarrants" xlink:type="locator"/>
    <link:label xlink:label="poai_ProceedsFromIssuanceAndExerciseOfWarrants-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_ProceedsFromIssuanceAndExerciseOfWarrants</link:label>
    <link:label xlink:label="poai_ProceedsFromIssuanceAndExerciseOfWarrants-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Proceeds from Issuance and Exercise of Warrants</link:label>
    <link:label xlink:label="poai_ProceedsFromIssuanceAndExerciseOfWarrants-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents proceeds from issuance and exercise of warrants.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ProceedsFromIssuanceAndExerciseOfWarrants" xlink:to="poai_ProceedsFromIssuanceAndExerciseOfWarrants-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ProceedsFromIssuanceAndExerciseOfWarrantsNet" xlink:label="poai_ProceedsFromIssuanceAndExerciseOfWarrantsNet" xlink:type="locator"/>
    <link:label xlink:label="poai_ProceedsFromIssuanceAndExerciseOfWarrantsNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_ProceedsFromIssuanceAndExerciseOfWarrantsNet</link:label>
    <link:label xlink:label="poai_ProceedsFromIssuanceAndExerciseOfWarrantsNet-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Proceeds from Issuance and Exercise of Warrants, Net</link:label>
    <link:label xlink:label="poai_ProceedsFromIssuanceAndExerciseOfWarrantsNet-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information related to net proceeds from issuance and exercise of warrants.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ProceedsFromIssuanceAndExerciseOfWarrantsNet" xlink:to="poai_ProceedsFromIssuanceAndExerciseOfWarrantsNet-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsDeferredIncome" xlink:label="us-gaap_DeferredTaxAssetsDeferredIncome" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsDeferredIncome-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred revenue</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsDeferredIncome" xlink:to="us-gaap_DeferredTaxAssetsDeferredIncome-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsDerivativeInstruments" xlink:label="us-gaap_DeferredTaxAssetsDerivativeInstruments" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsDerivativeInstruments-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsDerivativeInstruments</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsDerivativeInstruments-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Derivatives</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsDerivativeInstruments" xlink:to="us-gaap_DeferredTaxAssetsDerivativeInstruments-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsInventory" xlink:label="us-gaap_DeferredTaxAssetsInventory" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsInventory-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsInventory</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsInventory-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Inventory</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsInventory" xlink:to="us-gaap_DeferredTaxAssetsInventory-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets" xlink:label="us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Intangibles</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets" xlink:to="us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accruals and reserves</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals" xlink:to="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_Warrants2017Member" xlink:label="poai_Warrants2017Member" xlink:type="locator"/>
    <link:label xlink:label="poai_Warrants2017Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants 2017 [Member]</link:label>
    <link:label xlink:label="poai_Warrants2017Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents warrants 2017.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_Warrants2017Member" xlink:to="poai_Warrants2017Member-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_RisksAndUncertaintiesPolicyPolicyTextBlock" xlink:label="poai_RisksAndUncertaintiesPolicyPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="poai_RisksAndUncertaintiesPolicyPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Risks and Uncertainties Policy [Policy Text Block]</link:label>
    <link:label xlink:label="poai_RisksAndUncertaintiesPolicyPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Disclosure of accounting policy for risks and uncertainties common to companies in the medical device industry.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_RisksAndUncertaintiesPolicyPolicyTextBlock" xlink:to="poai_RisksAndUncertaintiesPolicyPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockOptions2017Member" xlink:label="poai_StockOptions2017Member" xlink:type="locator"/>
    <link:label xlink:label="poai_StockOptions2017Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Options 2017 [Member]</link:label>
    <link:label xlink:label="poai_StockOptions2017Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the stock options in 2017.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockOptions2017Member" xlink:to="poai_StockOptions2017Member-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ConversionOfStockSharesIssuedPercentageOfOutstandingShares" xlink:label="poai_ConversionOfStockSharesIssuedPercentageOfOutstandingShares" xlink:type="locator"/>
    <link:label xlink:label="poai_ConversionOfStockSharesIssuedPercentageOfOutstandingShares-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_ConversionOfStockSharesIssuedPercentageOfOutstandingShares</link:label>
    <link:label xlink:label="poai_ConversionOfStockSharesIssuedPercentageOfOutstandingShares-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Conversion of Stock, Shares Issued, Percentage of Outstanding Shares</link:label>
    <link:label xlink:label="poai_ConversionOfStockSharesIssuedPercentageOfOutstandingShares-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The percentage of shares issued in a conversion stock to the outstanding shares.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ConversionOfStockSharesIssuedPercentageOfOutstandingShares" xlink:to="poai_ConversionOfStockSharesIssuedPercentageOfOutstandingShares-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Computers, software and office equipment (Year)</link:label>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_PropertyPlantAndEquipmentUsefulLife</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLife-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ABAndAgentWarrantsMember" xlink:label="poai_ABAndAgentWarrantsMember" xlink:type="locator"/>
    <link:label xlink:label="poai_ABAndAgentWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">A, B and Agent Warrants [Member]</link:label>
    <link:label xlink:label="poai_ABAndAgentWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the A, B and agent warrants.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ABAndAgentWarrantsMember" xlink:to="poai_ABAndAgentWarrantsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash flow from operating activities:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ConversionFromSeriesEPreferredStockToCommonStockMember" xlink:label="poai_ConversionFromSeriesEPreferredStockToCommonStockMember" xlink:type="locator"/>
    <link:label xlink:label="poai_ConversionFromSeriesEPreferredStockToCommonStockMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Conversion from Series E Preferred Stock to Common Stock [Member]</link:label>
    <link:label xlink:label="poai_ConversionFromSeriesEPreferredStockToCommonStockMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the conversion of series E preferred stock to common stock.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ConversionFromSeriesEPreferredStockToCommonStockMember" xlink:to="poai_ConversionFromSeriesEPreferredStockToCommonStockMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherCapitalizedPropertyPlantAndEquipmentMember" xlink:label="us-gaap_OtherCapitalizedPropertyPlantAndEquipmentMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OtherCapitalizedPropertyPlantAndEquipmentMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Capitalized Property Plant and Equipment [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherCapitalizedPropertyPlantAndEquipmentMember" xlink:to="us-gaap_OtherCapitalizedPropertyPlantAndEquipmentMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Segment Reporting Information, by Segment [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StatementLineItems-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement [Line Items]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementLineItems-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent</link:label>
    <link:label xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accounts Receivable, Allowance for Credit Loss, Current</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NumberOfOperatingSegments" xlink:label="us-gaap_NumberOfOperatingSegments" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NumberOfOperatingSegments-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_NumberOfOperatingSegments</link:label>
    <link:label xlink:label="us-gaap_NumberOfOperatingSegments-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of Operating Segments</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NumberOfOperatingSegments" xlink:to="us-gaap_NumberOfOperatingSegments-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="us-gaap_AccountsReceivableNetCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AccountsReceivableNetCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accounts Receivable</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsReceivableNetCurrent" xlink:to="us-gaap_AccountsReceivableNetCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Compensation accruals</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits" xlink:to="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AdditionalPaidInCapital-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Additional Paid-in Capital</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapital" xlink:to="us-gaap_AdditionalPaidInCapital-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="us-gaap_StockholdersEquityAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockholdersEquityAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stockholders&#8217; Equity:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_StockholdersEquityAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsCharitableContributionCarryforwards" xlink:label="us-gaap_DeferredTaxAssetsCharitableContributionCarryforwards" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsCharitableContributionCarryforwards-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsCharitableContributionCarryforwards</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsCharitableContributionCarryforwards-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Charitable contribution carryover</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsCharitableContributionCarryforwards" xlink:to="us-gaap_DeferredTaxAssetsCharitableContributionCarryforwards-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_NotesReceivableInterestRateStatedPercentage" xlink:label="poai_NotesReceivableInterestRateStatedPercentage" xlink:type="locator"/>
    <link:label xlink:label="poai_NotesReceivableInterestRateStatedPercentage-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_NotesReceivableInterestRateStatedPercentage</link:label>
    <link:label xlink:label="poai_NotesReceivableInterestRateStatedPercentage-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Notes Receivable, Interest Rate, Stated Percentage</link:label>
    <link:label xlink:label="poai_NotesReceivableInterestRateStatedPercentage-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the simple interest rate for notes receivable.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_NotesReceivableInterestRateStatedPercentage" xlink:to="poai_NotesReceivableInterestRateStatedPercentage-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PromissoryNotesReceivableMember" xlink:label="poai_PromissoryNotesReceivableMember" xlink:type="locator"/>
    <link:label xlink:label="poai_PromissoryNotesReceivableMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Promissory Notes Receivable [Member]</link:label>
    <link:label xlink:label="poai_PromissoryNotesReceivableMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information pertaining to secured promissory notes receivable.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PromissoryNotesReceivableMember" xlink:to="poai_PromissoryNotesReceivableMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LeaseholdImprovementsMember" xlink:label="us-gaap_LeaseholdImprovementsMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LeaseholdImprovementsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Leasehold Improvements [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseholdImprovementsMember" xlink:to="us-gaap_LeaseholdImprovementsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ConvertiblePromissoryNoteMember" xlink:label="poai_ConvertiblePromissoryNoteMember" xlink:type="locator"/>
    <link:label xlink:label="poai_ConvertiblePromissoryNoteMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Convertible Promissory Note [Member]</link:label>
    <link:label xlink:label="poai_ConvertiblePromissoryNoteMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information about convertible promissory note.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ConvertiblePromissoryNoteMember" xlink:to="poai_ConvertiblePromissoryNoteMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherNonoperatingExpense" xlink:label="us-gaap_OtherNonoperatingExpense" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OtherNonoperatingExpense-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_OtherNonoperatingExpense</link:label>
    <link:label xlink:label="us-gaap_OtherNonoperatingExpense-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Other expense</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNonoperatingExpense" xlink:to="us-gaap_OtherNonoperatingExpense-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Lived Tangible Asset [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentByTypeAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Lived Tangible Asset [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_PropertyPlantAndEquipmentTypeDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentReportingDisclosureTextBlock" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SegmentReportingDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Segment Reporting Disclosure [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingDisclosureTextBlock" xlink:to="us-gaap_SegmentReportingDisclosureTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ScheduleOfSharebasedCompensationSharesAuthorizedUnderStockOptionAndWarrantPlansByExercisePriceRangeTableTextBlock" xlink:label="poai_ScheduleOfSharebasedCompensationSharesAuthorizedUnderStockOptionAndWarrantPlansByExercisePriceRangeTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="poai_ScheduleOfSharebasedCompensationSharesAuthorizedUnderStockOptionAndWarrantPlansByExercisePriceRangeTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Share-based Compensation Shares Authorized Under Stock Option and Warrant Plans by Exercise Price Range [Table Text Block]</link:label>
    <link:label xlink:label="poai_ScheduleOfSharebasedCompensationSharesAuthorizedUnderStockOptionAndWarrantPlansByExercisePriceRangeTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Tabular disclosure of option and warrant exercise prices, by grouped ranges, including the upper and lower limits of the price range, the number of shares under option, weighted average exercise price and remaining contractual option terms.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ScheduleOfSharebasedCompensationSharesAuthorizedUnderStockOptionAndWarrantPlansByExercisePriceRangeTableTextBlock" xlink:to="poai_ScheduleOfSharebasedCompensationSharesAuthorizedUnderStockOptionAndWarrantPlansByExercisePriceRangeTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockOptionsOneMember" xlink:label="poai_StockOptionsOneMember" xlink:type="locator"/>
    <link:label xlink:label="poai_StockOptionsOneMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Options One [Member]</link:label>
    <link:label xlink:label="poai_StockOptionsOneMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the first stock option.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockOptionsOneMember" xlink:to="poai_StockOptionsOneMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ChiefExecutiveOfficerMember" xlink:label="srt_ChiefExecutiveOfficerMember" xlink:type="locator"/>
    <link:label xlink:label="srt_ChiefExecutiveOfficerMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Chief Executive Officer [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ChiefExecutiveOfficerMember" xlink:to="srt_ChiefExecutiveOfficerMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockOptionsThreeMember" xlink:label="poai_StockOptionsThreeMember" xlink:type="locator"/>
    <link:label xlink:label="poai_StockOptionsThreeMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Options Three [Member]</link:label>
    <link:label xlink:label="poai_StockOptionsThreeMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the third stock option.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockOptionsThreeMember" xlink:to="poai_StockOptionsThreeMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherNonoperatingIncome" xlink:label="us-gaap_OtherNonoperatingIncome" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OtherNonoperatingIncome-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_OtherNonoperatingIncome</link:label>
    <link:label xlink:label="us-gaap_OtherNonoperatingIncome-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other Nonoperating Income</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNonoperatingIncome" xlink:to="us-gaap_OtherNonoperatingIncome-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockOptionsTwoMember" xlink:label="poai_StockOptionsTwoMember" xlink:type="locator"/>
    <link:label xlink:label="poai_StockOptionsTwoMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Options Two [Member]</link:label>
    <link:label xlink:label="poai_StockOptionsTwoMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the second stock options.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockOptionsTwoMember" xlink:to="poai_StockOptionsTwoMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="us-gaap_AssetsCurrentAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AssetsCurrentAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Current Assets:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_AssetsCurrentAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockOptionsFourMember" xlink:label="poai_StockOptionsFourMember" xlink:type="locator"/>
    <link:label xlink:label="poai_StockOptionsFourMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Options Four [Member]</link:label>
    <link:label xlink:label="poai_StockOptionsFourMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the fourth stock option.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockOptionsFourMember" xlink:to="poai_StockOptionsFourMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockPricePerShare" xlink:label="us-gaap_SaleOfStockPricePerShare" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SaleOfStockPricePerShare-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_SaleOfStockPricePerShare</link:label>
    <link:label xlink:label="us-gaap_SaleOfStockPricePerShare-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Sale of Stock, Price Per Share (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleOfStockPricePerShare" xlink:to="us-gaap_SaleOfStockPricePerShare-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration" xlink:to="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Deferred Tax Assets, Operating Loss Carryforwards, Not Subject to Expiration</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration" xlink:to="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations</link:label>
    <link:label xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations-label" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Cash and cash equivalents at beginning of year</link:label>
    <link:label xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations-label" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Cash and cash equivalents end of year</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoryPolicyTextBlock" xlink:label="us-gaap_InventoryPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_InventoryPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Inventory, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryPolicyTextBlock" xlink:to="us-gaap_InventoryPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PrivatePlacementMember" xlink:label="us-gaap_PrivatePlacementMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PrivatePlacementMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Private Placement [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrivatePlacementMember" xlink:to="us-gaap_PrivatePlacementMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect</link:label>
    <link:label xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net increase in cash and cash equivalents</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_Liabilities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_Liabilities</link:label>
    <link:label xlink:label="us-gaap_Liabilities-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total Liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_Liabilities-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_NetCashProvidedByUsedInFinancingActivities</link:label>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net cash provided by financing activities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SecuritiesPurchaseAgreementsMember" xlink:label="poai_SecuritiesPurchaseAgreementsMember" xlink:type="locator"/>
    <link:label xlink:label="poai_SecuritiesPurchaseAgreementsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Securities Purchase Agreements [Member]</link:label>
    <link:label xlink:label="poai_SecuritiesPurchaseAgreementsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information about "Securities Purchase Agreements".</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SecuritiesPurchaseAgreementsMember" xlink:to="poai_SecuritiesPurchaseAgreementsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SubsidiarySaleOfStockAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale of Stock [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SubsidiarySaleOfStockAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_DirectorMember" xlink:label="srt_DirectorMember" xlink:type="locator"/>
    <link:label xlink:label="srt_DirectorMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Director [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_DirectorMember" xlink:to="srt_DirectorMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale of Stock [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingIncomeLoss-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_OperatingIncomeLoss</link:label>
    <link:label xlink:label="us-gaap_OperatingIncomeLoss-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total operating loss</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_OperatingIncomeLoss-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_NetCashProvidedByUsedInOperatingActivities</link:label>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net cash used in operating activities:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SkylineMedicalEuropesOfficesLeaseMember" xlink:label="poai_SkylineMedicalEuropesOfficesLeaseMember" xlink:type="locator"/>
    <link:label xlink:label="poai_SkylineMedicalEuropesOfficesLeaseMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Skyline Medical Europe&#8217;s Offices Lease [Member]</link:label>
    <link:label xlink:label="poai_SkylineMedicalEuropesOfficesLeaseMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Lease arrangement for Skyline Medical Europe&#8217;s offices.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SkylineMedicalEuropesOfficesLeaseMember" xlink:to="poai_SkylineMedicalEuropesOfficesLeaseMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Prepaid Expense and Other Assets</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:to="us-gaap_PrepaidExpenseAndOtherAssetsCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_NetCashProvidedByUsedInInvestingActivities</link:label>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net cash used in investing activities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GrossProfit" xlink:label="us-gaap_GrossProfit" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_GrossProfit-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_GrossProfit</link:label>
    <link:label xlink:label="us-gaap_GrossProfit-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Gross profit</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GrossProfit" xlink:to="us-gaap_GrossProfit-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="us-gaap_CostOfGoodsAndServicesSold" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CostOfGoodsAndServicesSold-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cost of goods sold</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostOfGoodsAndServicesSold" xlink:to="us-gaap_CostOfGoodsAndServicesSold-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_CounterpartyNameAxis" xlink:label="srt_CounterpartyNameAxis" xlink:type="locator"/>
    <link:label xlink:label="srt_CounterpartyNameAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Counterparty Name [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_CounterpartyNameAxis" xlink:to="srt_CounterpartyNameAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RepurchaseAgreementCounterpartyNameDomain" xlink:label="srt_RepurchaseAgreementCounterpartyNameDomain" xlink:type="locator"/>
    <link:label xlink:label="srt_RepurchaseAgreementCounterpartyNameDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Counterparty Name [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RepurchaseAgreementCounterpartyNameDomain" xlink:to="srt_RepurchaseAgreementCounterpartyNameDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_WarrantTwoMember" xlink:label="poai_WarrantTwoMember" xlink:type="locator"/>
    <link:label xlink:label="poai_WarrantTwoMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrant Two [Member]</link:label>
    <link:label xlink:label="poai_WarrantTwoMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents warrant two.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantTwoMember" xlink:to="poai_WarrantTwoMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_WarrantOneMember" xlink:label="poai_WarrantOneMember" xlink:type="locator"/>
    <link:label xlink:label="poai_WarrantOneMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrant One [Member]</link:label>
    <link:label xlink:label="poai_WarrantOneMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents warrant one.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantOneMember" xlink:to="poai_WarrantOneMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_WarrantFourMember" xlink:label="poai_WarrantFourMember" xlink:type="locator"/>
    <link:label xlink:label="poai_WarrantFourMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrant Four [Member]</link:label>
    <link:label xlink:label="poai_WarrantFourMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents warrant four.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantFourMember" xlink:to="poai_WarrantFourMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="srt_ConsolidationItemsDomain" xlink:type="locator"/>
    <link:label xlink:label="srt_ConsolidationItemsDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Consolidation Items [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ConsolidationItemsDomain" xlink:to="srt_ConsolidationItemsDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_WarrantThreeMember" xlink:label="poai_WarrantThreeMember" xlink:type="locator"/>
    <link:label xlink:label="poai_WarrantThreeMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrant Three [Member]</link:label>
    <link:label xlink:label="poai_WarrantThreeMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents warrant three.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantThreeMember" xlink:to="poai_WarrantThreeMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ContractWithCustomerLiability" xlink:label="us-gaap_ContractWithCustomerLiability" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ContractWithCustomerLiability-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ContractWithCustomerLiability</link:label>
    <link:label xlink:label="us-gaap_ContractWithCustomerLiability-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Contract with Customer, Liability, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerLiability" xlink:to="us-gaap_ContractWithCustomerLiability-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SeriesAWarrantsMember" xlink:label="poai_SeriesAWarrantsMember" xlink:type="locator"/>
    <link:label xlink:label="poai_SeriesAWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Series A Warrants [Member]</link:label>
    <link:label xlink:label="poai_SeriesAWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information pertaining to Series A Warrants.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SeriesAWarrantsMember" xlink:to="poai_SeriesAWarrantsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLiabilities" xlink:label="us-gaap_DerivativeLiabilities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DerivativeLiabilities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DerivativeLiabilities</link:label>
    <link:label xlink:label="us-gaap_DerivativeLiabilities-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Derivative Liability, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeLiabilities" xlink:to="us-gaap_DerivativeLiabilities-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidationItemsAxis" xlink:label="srt_ConsolidationItemsAxis" xlink:type="locator"/>
    <link:label xlink:label="srt_ConsolidationItemsAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Consolidation Items [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ConsolidationItemsAxis" xlink:to="srt_ConsolidationItemsAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestPayableCurrentAndNoncurrent" xlink:label="us-gaap_InterestPayableCurrentAndNoncurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_InterestPayableCurrentAndNoncurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_InterestPayableCurrentAndNoncurrent</link:label>
    <link:label xlink:label="us-gaap_InterestPayableCurrentAndNoncurrent-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Interest Payable</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestPayableCurrentAndNoncurrent" xlink:to="us-gaap_InterestPayableCurrentAndNoncurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:label="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:to="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued</link:label>
    <link:label xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" xlink:to="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ClassOfWarrantOrRightOutstandingWeightedAverageRemainingContractualTerm" xlink:label="poai_ClassOfWarrantOrRightOutstandingWeightedAverageRemainingContractualTerm" xlink:type="locator"/>
    <link:label xlink:label="poai_ClassOfWarrantOrRightOutstandingWeightedAverageRemainingContractualTerm-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Weighted average remaining life, warrants (Year)</link:label>
    <link:label xlink:label="poai_ClassOfWarrantOrRightOutstandingWeightedAverageRemainingContractualTerm-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Weighted average remaining contractual term for warrants outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ClassOfWarrantOrRightOutstandingWeightedAverageRemainingContractualTerm" xlink:to="poai_ClassOfWarrantOrRightOutstandingWeightedAverageRemainingContractualTerm-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockOptions2013Member" xlink:label="poai_StockOptions2013Member" xlink:type="locator"/>
    <link:label xlink:label="poai_StockOptions2013Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Options 2013 [Member]</link:label>
    <link:label xlink:label="poai_StockOptions2013Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the stock options in 2013.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockOptions2013Member" xlink:to="poai_StockOptions2013Member-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockOptions2012Member" xlink:label="poai_StockOptions2012Member" xlink:type="locator"/>
    <link:label xlink:label="poai_StockOptions2012Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Options 2012 [Member]</link:label>
    <link:label xlink:label="poai_StockOptions2012Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the stock options in 2012.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockOptions2012Member" xlink:to="poai_StockOptions2012Member-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockOptions2015Member" xlink:label="poai_StockOptions2015Member" xlink:type="locator"/>
    <link:label xlink:label="poai_StockOptions2015Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Options 2015 [Member]</link:label>
    <link:label xlink:label="poai_StockOptions2015Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the stock options in 2015.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockOptions2015Member" xlink:to="poai_StockOptions2015Member-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskCreditRisk" xlink:label="us-gaap_ConcentrationRiskCreditRisk" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ConcentrationRiskCreditRisk-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Concentration Risk, Credit Risk, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskCreditRisk" xlink:to="us-gaap_ConcentrationRiskCreditRisk-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockOptions2014Member" xlink:label="poai_StockOptions2014Member" xlink:type="locator"/>
    <link:label xlink:label="poai_StockOptions2014Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Options 2014 [Member]</link:label>
    <link:label xlink:label="poai_StockOptions2014Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the stock options in 2014.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockOptions2014Member" xlink:to="poai_StockOptions2014Member-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_MaturityExtensionToMarch312021Member" xlink:label="poai_MaturityExtensionToMarch312021Member" xlink:type="locator"/>
    <link:label xlink:label="poai_MaturityExtensionToMarch312021Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Maturity Extension to March 31, 2021 [Member]</link:label>
    <link:label xlink:label="poai_MaturityExtensionToMarch312021Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to maturity extension to March 31, 2021.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_MaturityExtensionToMarch312021Member" xlink:to="poai_MaturityExtensionToMarch312021Member-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockOptions2016Member" xlink:label="poai_StockOptions2016Member" xlink:type="locator"/>
    <link:label xlink:label="poai_StockOptions2016Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Options 2016 [Member]</link:label>
    <link:label xlink:label="poai_StockOptions2016Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the stock options in 2016.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockOptions2016Member" xlink:to="poai_StockOptions2016Member-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:label="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Depreciation</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:to="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_June2021OfferingMember" xlink:label="poai_June2021OfferingMember" xlink:type="locator"/>
    <link:label xlink:label="poai_June2021OfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">June 2021 Offering [Member]</link:label>
    <link:label xlink:label="poai_June2021OfferingMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to the June 2021 offering.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_June2021OfferingMember" xlink:to="poai_June2021OfferingMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_AdjustmentsToAdditionalPaidInCapitalVestingExpenseAndOptionRepricing" xlink:label="poai_AdjustmentsToAdditionalPaidInCapitalVestingExpenseAndOptionRepricing" xlink:type="locator"/>
    <link:label xlink:label="poai_AdjustmentsToAdditionalPaidInCapitalVestingExpenseAndOptionRepricing-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Vesting expense and option repricing</link:label>
    <link:label xlink:label="poai_AdjustmentsToAdditionalPaidInCapitalVestingExpenseAndOptionRepricing-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents vesting expense and option repricing for adjustments to additional paid in capital.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_AdjustmentsToAdditionalPaidInCapitalVestingExpenseAndOptionRepricing" xlink:to="poai_AdjustmentsToAdditionalPaidInCapitalVestingExpenseAndOptionRepricing-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_SeriesBWarrantsMember" xlink:label="poai_SeriesBWarrantsMember" xlink:type="locator"/>
    <link:label xlink:label="poai_SeriesBWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Series B Warrants [Member]</link:label>
    <link:label xlink:label="poai_SeriesBWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represent series B warrants.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_SeriesBWarrantsMember" xlink:to="poai_SeriesBWarrantsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Gross proceeds</link:label>
    <link:label xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ProceedsFromIssuanceOrSaleOfEquity</link:label>
    <link:label xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Proceeds from Issuance or Sale of Equity, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:to="us-gaap_ProceedsFromIssuanceOrSaleOfEquity-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PaymentsForRepurchaseOfCommonStock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_PaymentsForRepurchaseOfCommonStock</link:label>
    <link:label xlink:label="us-gaap_PaymentsForRepurchaseOfCommonStock-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Repurchase of common stock upon vesting of restricted stock units</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:to="us-gaap_PaymentsForRepurchaseOfCommonStock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromWarrantExercises" xlink:label="us-gaap_ProceedsFromWarrantExercises" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ProceedsFromWarrantExercises-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Proceeds from exercise of warrants into common stock</link:label>
    <link:label xlink:label="us-gaap_ProceedsFromWarrantExercises-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Proceeds from Warrant Exercises</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromWarrantExercises" xlink:to="us-gaap_ProceedsFromWarrantExercises-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="us-gaap_RetainedEarningsMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RetainedEarningsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Retained Earnings [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsMember" xlink:to="us-gaap_RetainedEarningsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Proceeds from issuance of common stock, net</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="us-gaap_AdditionalPaidInCapitalMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AdditionalPaidInCapitalMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Additional Paid-in Capital [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapitalMember" xlink:to="us-gaap_AdditionalPaidInCapitalMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CommonStockMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common Stock [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockMember" xlink:to="us-gaap_CommonStockMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockMember" xlink:label="us-gaap_PreferredStockMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PreferredStockMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred Stock [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockMember" xlink:to="us-gaap_PreferredStockMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StatementEquityComponentsAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity Components [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_StatementEquityComponentsAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_EquityComponentDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity Component [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_EquityComponentDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebt" xlink:label="us-gaap_LongTermDebt" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LongTermDebt-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LongTermDebt</link:label>
    <link:label xlink:label="us-gaap_LongTermDebt-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Long-term Debt, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebt" xlink:to="us-gaap_LongTermDebt-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants issued, exercise price (in dollars per share)</link:label>
    <link:label xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightAxis" xlink:label="us-gaap_ClassOfWarrantOrRightAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ClassOfWarrantOrRightAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Class of Warrant or Right [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightAxis" xlink:to="us-gaap_ClassOfWarrantOrRightAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ClassOfWarrantOrRightIssuedDuringPeriod" xlink:label="poai_ClassOfWarrantOrRightIssuedDuringPeriod" xlink:type="locator"/>
    <link:label xlink:label="poai_ClassOfWarrantOrRightIssuedDuringPeriod-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Warrants issued (in shares)</link:label>
    <link:label xlink:label="poai_ClassOfWarrantOrRightIssuedDuringPeriod-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class of Warrant or Right Issued During Period (in shares)</link:label>
    <link:label xlink:label="poai_ClassOfWarrantOrRightIssuedDuringPeriod-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The number of warrants or rights issued during period.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ClassOfWarrantOrRightIssuedDuringPeriod" xlink:to="poai_ClassOfWarrantOrRightIssuedDuringPeriod-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightDomain" xlink:label="us-gaap_ClassOfWarrantOrRightDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ClassOfWarrantOrRightDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Class of Warrant or Right [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="us-gaap_ClassOfWarrantOrRightDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NotesPayable" xlink:label="us-gaap_NotesPayable" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NotesPayable-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Notes Payable</link:label>
    <link:label xlink:label="us-gaap_NotesPayable-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_NotesPayable</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesPayable" xlink:to="us-gaap_NotesPayable-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightOutstanding" xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares, warrants (in shares)</link:label>
    <link:label xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Shares, warrants (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightOutstanding" xlink:to="us-gaap_ClassOfWarrantOrRightOutstanding-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest</link:label>
    <link:label xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net loss before income tax benefit</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:to="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_IcfrAuditorAttestationFlag" xlink:label="dei_IcfrAuditorAttestationFlag" xlink:type="locator"/>
    <link:label xlink:label="dei_IcfrAuditorAttestationFlag-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">ICFR Auditor Attestation Flag</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_IcfrAuditorAttestationFlag" xlink:to="dei_IcfrAuditorAttestationFlag-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StateAndLocalJurisdictionMember" xlink:label="us-gaap_StateAndLocalJurisdictionMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StateAndLocalJurisdictionMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">State and Local Jurisdiction [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StateAndLocalJurisdictionMember" xlink:to="us-gaap_StateAndLocalJurisdictionMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis" xlink:label="us-gaap_IncomeTaxAuthorityAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxAuthorityAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income Tax Authority [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxAuthorityAxis" xlink:to="us-gaap_IncomeTaxAuthorityAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="us-gaap_IncomeTaxAuthorityDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxAuthorityDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income Tax Authority [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxAuthorityDomain" xlink:to="us-gaap_IncomeTaxAuthorityDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DomesticCountryMember" xlink:label="us-gaap_DomesticCountryMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DomesticCountryMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Domestic Tax Authority [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DomesticCountryMember" xlink:to="us-gaap_DomesticCountryMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignCountryMember" xlink:label="us-gaap_ForeignCountryMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ForeignCountryMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Foreign Tax Authority [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignCountryMember" xlink:to="us-gaap_ForeignCountryMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OfficeEquipmentMember" xlink:label="us-gaap_OfficeEquipmentMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OfficeEquipmentMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Office Equipment [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OfficeEquipmentMember" xlink:to="us-gaap_OfficeEquipmentMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentAnnualReport" xlink:label="dei_DocumentAnnualReport" xlink:type="locator"/>
    <link:label xlink:label="dei_DocumentAnnualReport-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Annual Report</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentAnnualReport" xlink:to="dei_DocumentAnnualReport-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscountCurrent" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Discount of note payable</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentUnamortizedDiscountCurrent" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscountCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:label="us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CashAndCashEquivalentsPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash and Cash Equivalents, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:to="us-gaap_CashAndCashEquivalentsPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscount" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscount" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtInstrumentUnamortizedDiscount-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DebtInstrumentUnamortizedDiscount</link:label>
    <link:label xlink:label="us-gaap_DebtInstrumentUnamortizedDiscount-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Instrument, Unamortized Discount, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentUnamortizedDiscount" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscount-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReceivablesPolicyTextBlock" xlink:label="us-gaap_ReceivablesPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ReceivablesPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Receivable [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ReceivablesPolicyTextBlock" xlink:to="us-gaap_ReceivablesPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityIncorporationStateCountryCode" xlink:label="dei_EntityIncorporationStateCountryCode" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityIncorporationStateCountryCode-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Incorporation, State or Country Code</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityIncorporationStateCountryCode" xlink:to="dei_EntityIncorporationStateCountryCode-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="us-gaap_UnrecognizedTaxBenefits" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_UnrecognizedTaxBenefits-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_UnrecognizedTaxBenefits</link:label>
    <link:label xlink:label="us-gaap_UnrecognizedTaxBenefits-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Unrecognized Tax Benefits, Ending Balance</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefits" xlink:to="us-gaap_UnrecognizedTaxBenefits-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AccountingPoliciesAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accounting Policies [Abstract]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_AccountingPoliciesAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SignificantAccountingPoliciesTextBlock" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Significant Accounting Policies [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SignificantAccountingPoliciesTextBlock" xlink:to="us-gaap_SignificantAccountingPoliciesTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentTransitionReport" xlink:label="dei_DocumentTransitionReport" xlink:type="locator"/>
    <link:label xlink:label="dei_DocumentTransitionReport-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Transition Report</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentTransitionReport" xlink:to="dei_DocumentTransitionReport-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:label="us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_BasisOfAccountingPolicyPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Basis of Accounting, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:to="us-gaap_BasisOfAccountingPolicyPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShortTermBorrowings" xlink:label="us-gaap_ShortTermBorrowings" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShortTermBorrowings-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShortTermBorrowings</link:label>
    <link:label xlink:label="us-gaap_ShortTermBorrowings-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Short-term Debt, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermBorrowings" xlink:to="us-gaap_ShortTermBorrowings-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityInteractiveDataCurrent" xlink:label="dei_EntityInteractiveDataCurrent" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityInteractiveDataCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Interactive Data Current</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityInteractiveDataCurrent" xlink:to="dei_EntityInteractiveDataCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_SecurityExchangeName" xlink:label="dei_SecurityExchangeName" xlink:type="locator"/>
    <link:label xlink:label="dei_SecurityExchangeName-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Security Exchange Name</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_SecurityExchangeName" xlink:to="dei_SecurityExchangeName-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_Security12bTitle" xlink:label="dei_Security12bTitle" xlink:type="locator"/>
    <link:label xlink:label="dei_Security12bTitle-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Title of 12(b) Security</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_Security12bTitle" xlink:to="dei_Security12bTitle-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_BusinessAcquisitionEquityInterestIssuedOrIssuableNumberOfSharesHeldInEscrow" xlink:label="poai_BusinessAcquisitionEquityInterestIssuedOrIssuableNumberOfSharesHeldInEscrow" xlink:type="locator"/>
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    <link:label xlink:label="poai_BusinessAcquisitionEquityInterestIssuedOrIssuableNumberOfSharesHeldInEscrow-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Number of shares of equity interests issued or issuable to acquire entity being held in escrow.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_BusinessAcquisitionEquityInterestIssuedOrIssuableNumberOfSharesHeldInEscrow" xlink:to="poai_BusinessAcquisitionEquityInterestIssuedOrIssuableNumberOfSharesHeldInEscrow-label" xlink:type="arc"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromRelatedPartyDebt" xlink:to="us-gaap_ProceedsFromRelatedPartyDebt-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_TotalIssuancesMember" xlink:label="poai_TotalIssuancesMember" xlink:type="locator"/>
    <link:label xlink:label="poai_TotalIssuancesMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Total Issuances [Member]</link:label>
    <link:label xlink:label="poai_TotalIssuancesMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to total issuances.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_TotalIssuancesMember" xlink:to="poai_TotalIssuancesMember-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_ReceivableTypeDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Receivable [Domain]</link:label>
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    <link:label xlink:label="us-gaap_NonmonetaryTransactionTypeAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Nonmonetary Transaction Type [Axis]</link:label>
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    <link:label xlink:label="us-gaap_StatementBusinessSegmentsAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Segments [Axis]</link:label>
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    <link:label xlink:label="us-gaap_SegmentDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Segments [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentDomain" xlink:to="us-gaap_SegmentDomain-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effect of diluted stock options, warrants and preferred stock (1) (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:to="us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:label="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Weighted average shares used in computation - basic and diluted (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:to="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:type="locator"/>
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    <link:label xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_ProceedsFromNotesPayable-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ProceedsFromNotesPayable</link:label>
    <link:label xlink:label="us-gaap_ProceedsFromNotesPayable-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Proceeds from Notes Payable, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromNotesPayable" xlink:to="us-gaap_ProceedsFromNotesPayable-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_EffectiveIncomeTaxRateReconciliationStateNetOperatingLossAdjustmentAmount" xlink:label="poai_EffectiveIncomeTaxRateReconciliationStateNetOperatingLossAdjustmentAmount" xlink:type="locator"/>
    <link:label xlink:label="poai_EffectiveIncomeTaxRateReconciliationStateNetOperatingLossAdjustmentAmount-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">NOL adjustments</link:label>
    <link:label xlink:label="poai_EffectiveIncomeTaxRateReconciliationStateNetOperatingLossAdjustmentAmount-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations, attributable to increase (decrease) state net operating loss adjustment.</link:label>
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    <link:loc xlink:href="poai-20211231.xsd#poai_EffectiveIncomeTaxRateReconciliationStateTaxRateAdjustmentAmount" xlink:label="poai_EffectiveIncomeTaxRateReconciliationStateTaxRateAdjustmentAmount" xlink:type="locator"/>
    <link:label xlink:label="poai_EffectiveIncomeTaxRateReconciliationStateTaxRateAdjustmentAmount-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_EffectiveIncomeTaxRateReconciliationStateTaxRateAdjustmentAmount</link:label>
    <link:label xlink:label="poai_EffectiveIncomeTaxRateReconciliationStateTaxRateAdjustmentAmount-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">State rate adjustment</link:label>
    <link:label xlink:label="poai_EffectiveIncomeTaxRateReconciliationStateTaxRateAdjustmentAmount-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations, attributable to increase (decrease) in the state income tax rates.</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromShortTermDebt" xlink:label="us-gaap_ProceedsFromShortTermDebt" xlink:type="locator"/>
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    <link:loc xlink:href="poai-20211231.xsd#poai_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxBenefitAmount" xlink:label="poai_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxBenefitAmount" xlink:type="locator"/>
    <link:label xlink:label="poai_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxBenefitAmount-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Foreign tax benefit</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxBenefitAmount" xlink:to="poai_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxBenefitAmount-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerShareBasicAndDiluted" xlink:label="us-gaap_EarningsPerShareBasicAndDiluted" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_EarningsPerShareBasicAndDiluted-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_EarningsPerShareBasicAndDiluted</link:label>
    <link:label xlink:label="us-gaap_EarningsPerShareBasicAndDiluted-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Loss per common share - basic and diluted (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareBasicAndDiluted" xlink:to="us-gaap_EarningsPerShareBasicAndDiluted-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLossCarryforwards" xlink:label="us-gaap_OperatingLossCarryforwards" xlink:type="locator"/>
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    <link:label xlink:label="us-gaap_OperatingLossCarryforwards-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating Loss Carryforwards, Total</link:label>
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    <link:loc xlink:href="poai-20211231.xsd#poai_DeferredTaxAssetsOperatingLossCarryforwardsAndCredits" xlink:label="poai_DeferredTaxAssetsOperatingLossCarryforwardsAndCredits" xlink:type="locator"/>
    <link:label xlink:label="poai_DeferredTaxAssetsOperatingLossCarryforwardsAndCredits-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_DeferredTaxAssetsOperatingLossCarryforwardsAndCredits</link:label>
    <link:label xlink:label="poai_DeferredTaxAssetsOperatingLossCarryforwardsAndCredits-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">NOL and credits</link:label>
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    <link:loc xlink:href="poai-20211231.xsd#poai_DeferredTaxAssetsNQSOCompensation" xlink:label="poai_DeferredTaxAssetsNQSOCompensation" xlink:type="locator"/>
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    <link:label xlink:label="us-gaap_OperatingLossCarryforwardsValuationAllowance-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating Loss Carryforwards, Valuation Allowance, Total</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementTable-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_DeferredTaxAssetsLiabilitiesGross" xlink:label="poai_DeferredTaxAssetsLiabilitiesGross" xlink:type="locator"/>
    <link:label xlink:label="poai_DeferredTaxAssetsLiabilitiesGross-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_DeferredTaxAssetsLiabilitiesGross</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_DeferredTaxAssetsLiabilitiesGross" xlink:to="poai_DeferredTaxAssetsLiabilitiesGross-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_StatementOfFinancialPositionAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement of Financial Position [Abstract]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StatementOfFinancialPositionAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ClassOfWarrantOrRightNumberOfWarrantsVestedAndExercisable" xlink:label="poai_ClassOfWarrantOrRightNumberOfWarrantsVestedAndExercisable" xlink:type="locator"/>
    <link:label xlink:label="poai_ClassOfWarrantOrRightNumberOfWarrantsVestedAndExercisable-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_ClassOfWarrantOrRightNumberOfWarrantsVestedAndExercisable</link:label>
    <link:label xlink:label="poai_ClassOfWarrantOrRightNumberOfWarrantsVestedAndExercisable-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class of Warrant or Right Number of Warrants Vested and Exercisable (in shares)</link:label>
    <link:label xlink:label="poai_ClassOfWarrantOrRightNumberOfWarrantsVestedAndExercisable-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The number of warrants that are fully vested and exercisable at the balance sheet date.</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Weighted average common shares outstanding-basic (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_BusinessAcquisitionAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Business Acquisition [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_StockIncentivePlan2012Member" xlink:label="poai_StockIncentivePlan2012Member" xlink:type="locator"/>
    <link:label xlink:label="poai_StockIncentivePlan2012Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Incentive Plan 2012 [Member]</link:label>
    <link:label xlink:label="poai_StockIncentivePlan2012Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents Stock Incentive Plan 2012.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_StockIncentivePlan2012Member" xlink:to="poai_StockIncentivePlan2012Member-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Business Acquisition, Acquiree [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:label="us-gaap_StatementOfCashFlowsAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StatementOfCashFlowsAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement of Cash Flows [Abstract]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_StatementOfCashFlowsAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LeaseContractualTermDomain" xlink:label="us-gaap_LeaseContractualTermDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LeaseContractualTermDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lease Contractual Term [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseContractualTermDomain" xlink:to="us-gaap_LeaseContractualTermDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StatementOfStockholdersEquityAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement of Stockholders' Equity [Abstract]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="us-gaap_StatementOfStockholdersEquityAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LeaseContractualTermAxis" xlink:label="us-gaap_LeaseContractualTermAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LeaseContractualTermAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lease Contractual Term [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseContractualTermAxis" xlink:to="us-gaap_LeaseContractualTermAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeStatementAbstract" xlink:label="us-gaap_IncomeStatementAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeStatementAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income Statement [Abstract]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_IncomeStatementAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceOfDebt" xlink:label="us-gaap_ProceedsFromIssuanceOfDebt" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ProceedsFromIssuanceOfDebt-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Proceeds from debt issuance</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfDebt" xlink:to="us-gaap_ProceedsFromIssuanceOfDebt-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RepaymentsOfDebt" xlink:label="us-gaap_RepaymentsOfDebt" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RepaymentsOfDebt-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_RepaymentsOfDebt</link:label>
    <link:label xlink:label="us-gaap_RepaymentsOfDebt-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Repayments of Debt</link:label>
    <link:label xlink:label="us-gaap_RepaymentsOfDebt-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Repayment of debt</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepaymentsOfDebt" xlink:to="us-gaap_RepaymentsOfDebt-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmbeddedDerivativeNoLongerBifurcatedAmountReclassifiedToStockholdersEquity" xlink:label="us-gaap_EmbeddedDerivativeNoLongerBifurcatedAmountReclassifiedToStockholdersEquity" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_EmbeddedDerivativeNoLongerBifurcatedAmountReclassifiedToStockholdersEquity-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_EmbeddedDerivativeNoLongerBifurcatedAmountReclassifiedToStockholdersEquity</link:label>
    <link:label xlink:label="us-gaap_EmbeddedDerivativeNoLongerBifurcatedAmountReclassifiedToStockholdersEquity-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Reclassification of Warrant liabilities to Equity</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmbeddedDerivativeNoLongerBifurcatedAmountReclassifiedToStockholdersEquity" xlink:to="us-gaap_EmbeddedDerivativeNoLongerBifurcatedAmountReclassifiedToStockholdersEquity-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmbeddedDerivativeGainLossOnEmbeddedDerivativeNet" xlink:label="us-gaap_EmbeddedDerivativeGainLossOnEmbeddedDerivativeNet" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_EmbeddedDerivativeGainLossOnEmbeddedDerivativeNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_EmbeddedDerivativeGainLossOnEmbeddedDerivativeNet</link:label>
    <link:label xlink:label="us-gaap_EmbeddedDerivativeGainLossOnEmbeddedDerivativeNet-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Embedded Derivative, Gain (Loss) on Embedded Derivative, Net, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmbeddedDerivativeGainLossOnEmbeddedDerivativeNet" xlink:to="us-gaap_EmbeddedDerivativeGainLossOnEmbeddedDerivativeNet-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:label="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued</link:label>
    <link:label xlink:label="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:to="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Deferred Tax Assets and Liabilities [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:to="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_WarrantsIssuedDebtIssuance" xlink:label="poai_WarrantsIssuedDebtIssuance" xlink:type="locator"/>
    <link:label xlink:label="poai_WarrantsIssuedDebtIssuance-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_WarrantsIssuedDebtIssuance</link:label>
    <link:label xlink:label="poai_WarrantsIssuedDebtIssuance-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Warrants issued pursuant to debt issuance</link:label>
    <link:label xlink:label="poai_WarrantsIssuedDebtIssuance-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents warrant issued pursuant to debt issuance.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_WarrantsIssuedDebtIssuance" xlink:to="poai_WarrantsIssuedDebtIssuance-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:to="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_EquityLinePurchaseAgreementMember" xlink:label="poai_EquityLinePurchaseAgreementMember" xlink:type="locator"/>
    <link:label xlink:label="poai_EquityLinePurchaseAgreementMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity Line Purchase Agreement [Member]</link:label>
    <link:label xlink:label="poai_EquityLinePurchaseAgreementMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information related to equity line purchase agreement.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_EquityLinePurchaseAgreementMember" xlink:to="poai_EquityLinePurchaseAgreementMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccruedExpenses" xlink:label="poai_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccruedExpenses" xlink:type="locator"/>
    <link:label xlink:label="poai_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccruedExpenses-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccruedExpenses</link:label>
    <link:label xlink:label="poai_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccruedExpenses-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Accrued expenses</link:label>
    <link:label xlink:label="poai_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccruedExpenses-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amount of accrued expenses, assumed at the acquisition date.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccruedExpenses" xlink:to="poai_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccruedExpenses-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_EffectOfCovid19PandemicPolicyTextBlock" xlink:label="poai_EffectOfCovid19PandemicPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="poai_EffectOfCovid19PandemicPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effect of Covid-19 Pandemic [Policy Text Block]</link:label>
    <link:label xlink:label="poai_EffectOfCovid19PandemicPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The disclosure of the accounting policy for effects of COVID-19 pandemic.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_EffectOfCovid19PandemicPolicyTextBlock" xlink:to="poai_EffectOfCovid19PandemicPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_InducementSharesIssuedForDebtExtension" xlink:label="poai_InducementSharesIssuedForDebtExtension" xlink:type="locator"/>
    <link:label xlink:label="poai_InducementSharesIssuedForDebtExtension-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_InducementSharesIssuedForDebtExtension</link:label>
    <link:label xlink:label="poai_InducementSharesIssuedForDebtExtension-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Inducement shares issued pursuant to convertible debt</link:label>
    <link:label xlink:label="poai_InducementSharesIssuedForDebtExtension-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The value of inducement shares issued for debt extension.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_InducementSharesIssuedForDebtExtension" xlink:to="poai_InducementSharesIssuedForDebtExtension-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxReconciliationOtherAdjustments" xlink:label="us-gaap_IncomeTaxReconciliationOtherAdjustments" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationOtherAdjustments-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncomeTaxReconciliationOtherAdjustments</link:label>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationOtherAdjustments-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Other</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationOtherAdjustments" xlink:to="us-gaap_IncomeTaxReconciliationOtherAdjustments-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash flow from financing activities:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ConversionOfSeriesEPreferredStockMember" xlink:label="poai_ConversionOfSeriesEPreferredStockMember" xlink:type="locator"/>
    <link:label xlink:label="poai_ConversionOfSeriesEPreferredStockMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Conversion of Series E Preferred Stock [Member]</link:label>
    <link:label xlink:label="poai_ConversionOfSeriesEPreferredStockMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to the conversion of series E preferred stock.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ConversionOfSeriesEPreferredStockMember" xlink:to="poai_ConversionOfSeriesEPreferredStockMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="us-gaap_OtherLiabilitiesNoncurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OtherLiabilitiesNoncurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Long Term Liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilitiesNoncurrent" xlink:to="us-gaap_OtherLiabilitiesNoncurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance</link:label>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Valuation allowance increase</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:to="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ConversionFromSeriesDPreferredStockToCommonStockMember" xlink:label="poai_ConversionFromSeriesDPreferredStockToCommonStockMember" xlink:type="locator"/>
    <link:label xlink:label="poai_ConversionFromSeriesDPreferredStockToCommonStockMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Conversion from Series D Preferred Stock to Common Stock [Member]</link:label>
    <link:label xlink:label="poai_ConversionFromSeriesDPreferredStockToCommonStockMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents conversion from series D preferred stock to common stock.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ConversionFromSeriesDPreferredStockToCommonStockMember" xlink:to="poai_ConversionFromSeriesDPreferredStockToCommonStockMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CorporateNonSegmentMember" xlink:label="us-gaap_CorporateNonSegmentMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CorporateNonSegmentMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Corporate, Non-Segment [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CorporateNonSegmentMember" xlink:to="us-gaap_CorporateNonSegmentMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeriesDPreferredStockMember" xlink:label="us-gaap_SeriesDPreferredStockMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SeriesDPreferredStockMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Series D Preferred Stock [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SeriesDPreferredStockMember" xlink:to="us-gaap_SeriesDPreferredStockMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_BridgeNotesMember" xlink:label="poai_BridgeNotesMember" xlink:type="locator"/>
    <link:label xlink:label="poai_BridgeNotesMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Bridge Notes [Member]</link:label>
    <link:label xlink:label="poai_BridgeNotesMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to bridge notes.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_BridgeNotesMember" xlink:to="poai_BridgeNotesMember-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_IssuanceOrSaleOfEquityCanBeRaised" xlink:label="poai_IssuanceOrSaleOfEquityCanBeRaised" xlink:type="locator"/>
    <link:label xlink:label="poai_IssuanceOrSaleOfEquityCanBeRaised-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_IssuanceOrSaleOfEquityCanBeRaised</link:label>
    <link:label xlink:label="poai_IssuanceOrSaleOfEquityCanBeRaised-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Issuance or Sale of Equity, Can Be Raised</link:label>
    <link:label xlink:label="poai_IssuanceOrSaleOfEquityCanBeRaised-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the amount of issuance or sale of equity can be raised.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_IssuanceOrSaleOfEquityCanBeRaised" xlink:to="poai_IssuanceOrSaleOfEquityCanBeRaised-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockholdersEquity-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_StockholdersEquity</link:label>
    <link:label xlink:label="us-gaap_StockholdersEquity-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total Stockholders' Equity</link:label>
    <link:label xlink:label="us-gaap_StockholdersEquity-label" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Balance</link:label>
    <link:label xlink:label="us-gaap_StockholdersEquity-label" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Balance</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ReverseStockSplitMember" xlink:label="poai_ReverseStockSplitMember" xlink:type="locator"/>
    <link:label xlink:label="poai_ReverseStockSplitMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Reverse Stock Split [Member]</link:label>
    <link:label xlink:label="poai_ReverseStockSplitMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The conversion of a reverse stock split where there is a reduction in the shares outstanding.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ReverseStockSplitMember" xlink:to="poai_ReverseStockSplitMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired</link:label>
    <link:label xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Acquisition of zPREDICTA, net of cash acquired</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:to="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpense" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpense" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpense-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncomeTaxReconciliationNondeductibleExpense</link:label>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpense-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Nondeductible/nontaxable items</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationNondeductibleExpense" xlink:to="us-gaap_IncomeTaxReconciliationNondeductibleExpense-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StatementClassOfStockAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Class of Stock [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_StatementClassOfStockAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Goodwill impairment</link:label>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses" xlink:to="us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ClassOfStockDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Class of Stock [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_ClassOfStockDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities</link:label>
    <link:label xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Deferred tax liability</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:to="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue</link:label>
    <link:label xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Deferred revenue</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PaymentsToAcquireBusinessesGross-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_PaymentsToAcquireBusinessesGross</link:label>
    <link:label xlink:label="us-gaap_PaymentsToAcquireBusinessesGross-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Payments to Acquire Businesses, Gross</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireBusinessesGross" xlink:to="us-gaap_PaymentsToAcquireBusinessesGross-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_ValuationAllowancePercentage" xlink:label="poai_ValuationAllowancePercentage" xlink:type="locator"/>
    <link:label xlink:label="poai_ValuationAllowancePercentage-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">poai_ValuationAllowancePercentage</link:label>
    <link:label xlink:label="poai_ValuationAllowancePercentage-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Valuation Allowance Percentage</link:label>
    <link:label xlink:label="poai_ValuationAllowancePercentage-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Percentage valuation allowance that is appropriate for deferred tax assets and state income taxes.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_ValuationAllowancePercentage" xlink:to="poai_ValuationAllowancePercentage-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_PlacementAgentWarrantsMember" xlink:label="poai_PlacementAgentWarrantsMember" xlink:type="locator"/>
    <link:label xlink:label="poai_PlacementAgentWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Placement Agent Warrants [Member]</link:label>
    <link:label xlink:label="poai_PlacementAgentWarrantsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to the placement agent warrants.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="poai_PlacementAgentWarrantsMember" xlink:to="poai_PlacementAgentWarrantsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDerivativeLiabilitiesAtFairValueTableTextBlock" xlink:label="us-gaap_ScheduleOfDerivativeLiabilitiesAtFairValueTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfDerivativeLiabilitiesAtFairValueTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Derivative Liabilities at Fair Value [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDerivativeLiabilitiesAtFairValueTableTextBlock" xlink:to="us-gaap_ScheduleOfDerivativeLiabilitiesAtFairValueTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="us-gaap_OperatingSegmentsMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingSegmentsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Segments [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingSegmentsMember" xlink:to="us-gaap_OperatingSegmentsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquireLoansReceivable" xlink:label="us-gaap_PaymentsToAcquireLoansReceivable" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PaymentsToAcquireLoansReceivable-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_PaymentsToAcquireLoansReceivable</link:label>
    <link:label xlink:label="us-gaap_PaymentsToAcquireLoansReceivable-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Loan activities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireLoansReceivable" xlink:to="us-gaap_PaymentsToAcquireLoansReceivable-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Options, upper limit (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Shares, options (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Exercise Price Range [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:label="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes</link:label>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">State tax benefit, net of federal taxes</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:to="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes-label" xlink:type="arc"/>
    <link:loc xlink:href="poai-20211231.xsd#poai_EquityIncentivePlanMember" xlink:label="poai_EquityIncentivePlanMember" xlink:type="locator"/>
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