BRCA1 and breast cancer: We and others have investigated putative risk factors, and a number of published studies have implicated candidate genes (for example, AIB1 in BRCA1, RAD51 in BRCA2) and SNPs in FGFR2, MAP3K1, TNRC9, LSP1, and 2q35 previously identified from genome-wide association studies of breast cancer as modifiers of breast cancer or ovarian cancer penetrance in women who carry germline BRCA1 or BRCA2 mutations [9-13,49].