Here, we contrast the pattern and clinical consequences of RB1 loss in HGSC with other epithelial ovarian cancer subtypes, investigate the relevance of co-occurring BRCA1 or BRCA2 alterations and RB1 loss in patients with HGSC, and explore the functional effects of combined BRCA and RB1 impairment in HGSC cell lines. The gene discussed is BRCA1; the disease is ovarian carcinoma.