BRCA1/2−/− cases accounted for approximately half (50.6%) of HRD cases in tissues recognized for germline BRCA1/2-linked cancer susceptibility (e.g. OV: Ovarian serous cystadenocarcinoma, TNBC, ER+ or HER2+ BRCA: Breast invasive carcinoma samples, PAAD: Pancreatic adenocarcinoma, PRAD: Prostate adenocarcinoma). The gene discussed is ERBB2; the disease is cancer.