PARPis are licensed as maintenance treatment for recurrent ovarian cancer after response (CR/PR) to platinum-based chemotherapy independent of BRCA1/2 status and also as maintenance treatment for primary high-grade serous ovarian, fallopian tube, or peritoneal cancer after response (CR/PR) to platinum-based chemotherapy in BRCA1/2 mutation carriers. The gene discussed is BRCA1; the disease is ovarian carcinoma.