To determine the activities of the PARP inhibitors and ATO in the HR-proficient ovarian cancer cells, we assembled a panel of six ovarian cancer cell lines including A2780, CAOV3, OVCAR3, SKOV3, HO8910, and UWB1.289 cells, and selected for HR-proficient cells based on their BRCA status and HRD score analyzed by BGI DNA sequencing (Fig. 1A). The gene discussed is PARP1; the disease is ovarian cancer.