A study reported 59% of fusions in specimens of recurrentHGSOC with the highest MDR1 expression.72 Most PARPi are MDR1substrates, and particularly prior treatment with paclitaxel may induce MDR1upregulation and indirectly induce PARPi resistance.73Clinical findings with MDR1 inhibitors in drug resistance settings weredisappointing.74,75 The addition of MDR1inhibitors to PARPi in patients with ABCB1 mutations hasnot yet been explored in clinical trials.76 In addition, otherfactors are responsible for PARPi bioavailability in the tumor cells. Here, ABCB1 is linked to neoplasm.