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  <xsd:element id="bcab_ExclusiveLicenseAgreementAbstract" name="ExclusiveLicenseAgreementAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
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  <xsd:element id="bcab_AccruedResearchAndDevelopmentExpenseCurrent" name="AccruedResearchAndDevelopmentExpenseCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="bcab_AgreementTransactionPrice" name="AgreementTransactionPrice" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="bcab_AmendedMilestonePayments" name="AmendedMilestonePayments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="bcab_AssetsOrLiabilitiesAssociatedWithRelatedPartyVariableInterest" name="AssetsOrLiabilitiesAssociatedWithRelatedPartyVariableInterest" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="bcab_ChangeInFairValueAndPushdownOfProfitsInterestLiability" name="ChangeInFairValueAndPushdownOfProfitsInterestLiability" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
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  <xsd:element id="bcab_CompanyFormationDate" name="CompanyFormationDate" type="xbrli:gYearMonthItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="bcab_DebtInstrumentOutstandingPrincipalAmount" name="DebtInstrumentOutstandingPrincipalAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="bcab_DebtInstrumentSettledDate" name="DebtInstrumentSettledDate" type="xbrli:gYearMonthItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="bcab_EquityInterestInRelatedParty" name="EquityInterestInRelatedParty" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="bcab_EquityIssuanceCostsIncludedInAccountsPayableAndAccruedExpenses" name="EquityIssuanceCostsIncludedInAccountsPayableAndAccruedExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="bcab_GeneralAndAdministrativeExpenseRelatedParty" name="GeneralAndAdministrativeExpenseRelatedParty" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="bcab_IncreaseDecreaseInDeferredRent" name="IncreaseDecreaseInDeferredRent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="bcab_IncrementalFairValue" name="IncrementalFairValue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="bcab_LoansFromPrincipalOwnersAndOfficers" name="LoansFromPrincipalOwnersAndOfficers" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="bcab_LongTermAccruedInterest" name="LongTermAccruedInterest" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="bcab_LumpSumSalaryPaymentAndTargetBonus" name="LumpSumSalaryPaymentAndTargetBonus" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="bcab_NonCashChargeRelatedToModifiedEquityAwards" name="NonCashChargeRelatedToModifiedEquityAwards" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="bcab_NumberOfAcceleratedFullVestingEquityAwardsIncludingRestrictedStockUnits" name="NumberOfAcceleratedFullVestingEquityAwardsIncludingRestrictedStockUnits" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="bcab_NumberOfAcceleratedFullVestingEquityAwardsIncludingStockOptions" name="NumberOfAcceleratedFullVestingEquityAwardsIncludingStockOptions" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
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  <xsd:element id="bcab_OtherPrepaidExpensesAndCurrentAssets" name="OtherPrepaidExpensesAndCurrentAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
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  <xsd:element id="bcab_PerformanceObligationsMilestonePayment" name="PerformanceObligationsMilestonePayment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
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  <xsd:element id="bcab_SubsequentSaleOfConvertiblePreferredStockToNewInvestorsShares" name="SubsequentSaleOfConvertiblePreferredStockToNewInvestorsShares" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="bcab_UpfrontNonRefundablePayment" name="UpfrontNonRefundablePayment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="bcab_WarrantsForThePurchaseOfCommonStock" name="WarrantsForThePurchaseOfCommonStock" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="bcab_OrganizationAndSummaryOfSignificantAccountingPoliciesLineItems" name="OrganizationAndSummaryOfSignificantAccountingPoliciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="bcab_AmendedBeiGeneCollaborationMember" name="AmendedBeiGeneCollaborationMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
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  <xsd:element id="bcab_CommonSockWrantsMember" name="CommonSockWrantsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="bcab_ConstructionInProcessMember" name="ConstructionInProcessMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
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  <xsd:element id="bcab_DecemberSeventyTwoThousandTwentyOneMember" name="DecemberSeventyTwoThousandTwentyOneMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="bcab_EmployeesStockPurchasePlanMember" name="EmployeesStockPurchasePlanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
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  <xsd:element id="bcab_FurnitureFixturesAndOfficeEquipmentMember" name="FurnitureFixturesAndOfficeEquipmentMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
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  <xsd:element id="bcab_TwoThousandTwentyPlanMember" name="TwoThousandTwentyPlanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
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  <xsd:element id="bcab_PrinciplesOfConsolidationAndDeconsolidationPolicyTextBlock" name="PrinciplesOfConsolidationAndDeconsolidationPolicyTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
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  <xsd:element id="bcab_AllocationOfEquityBasedCompensationForClassBUnitsTableTextBlock" name="AllocationOfEquityBasedCompensationForClassBUnitsTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
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  <xsd:element id="bcab_ExclusiveLicenseAgreementWithEXUMABiotechCorpTextBlock" name="ExclusiveLicenseAgreementWithEXUMABiotechCorpTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
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</xsd:schema>
