BRCA1 and hepatocellular carcinoma: Thus, though MDA-MB-436 showed the highest sensitivity to Olaparib (IC50 = 10.21 μM), as would be predicted for BRCA1-mutated cells [8], the Olaparib response of HCC-1937 cells was indistinguishable from the one in the luminal cell lines ZR75-1 and MCF7.