Six loci (at TOX3, 2q35, 6q25.1, 19p13, CASP8 and wild-type copy of BRCA1) are now known to be associated with breast cancer risk for BRCA1 mutation carriers; a further 10 loci (at FGFR2, TOX3, MAP3K1, LSP1, 2q35, SLC4A7, 5p12, 1p11.2, ZNF365 and RAD51) have been associated with breast cancer risk for BRCA2 carriers. The gene discussed is BRCA1; the disease is breast carcinoma.