For example, 50% of high-grade serous ovarian cancers (HGSOC) exhibit defective DNA repair by inactivation of the homologous recombination due to germline and somatic mutations in BRCA1 (11%), BRCA2 (9%) and promoter hypermethylation of BRCA1 (10%). The gene discussed is BRCA1; the disease is ovarian serous adenocarcinoma.