Importantly, STAT3 blockade led to Olaparib-resistant cell growth inhibition, and lower Napabucasin concentrations re-sensitized resistant BRCA-wildtype and BRCA2-mutated ovarian cancer cells to Olaparib in vitro, further supporting the notion that STAT3 activity promotes PARPi resistance. This evidence concerns the gene BRCA2 and ovarian carcinoma.