Recently, exploratory sub-group analyses for PFS demonstrated that the hazard ratio favoured olaparib versus chemotherapy for BRCA carriers of either subtype.61 In addition, the ABRAZO study showed similar response rates to talazoparib for BRCA1/2m carriers with metastatic ER-positive and TNBC: 29% and 26%, respectively.65 Although larger studies are needed, these results indicate that ER-positive BC in BRCA1/2m carriers are responsive to PARPi. Here, BRCA1 is linked to breast cancer.