This resulted in a comprehensive targeted sequencing effort that examined 1303 candidate BC predisposition genes and 14 previously proposed hereditary breast and ovarian cancer (HBOC) genes in up to 5770 non-BRCA1/2 index cases and 5741 cancer-free population controls, providing a highly powered survey of the monogenic contributions to the heritable risk of BC. The gene discussed is BRCA1; the disease is cancer.