Considering all reported modifying loci by the CIMBA consortium, there are now six loci in total that are associated with breast cancer risk for BRCA1 mutation carriers (19p13, 6q25.1, 12p11, TOX3, 2q35 and CASP8) and 13 loci which are known to be associated with BRCA2 breast cancer risk (FGFR2, TOX3, MAP3K1, LSP1, 2q35, SLC4A7, 5p12, 1p11.2, ZNF365, CDKN2A/B, 9q31.2, 12q24 and RAD51). This evidence concerns the gene MAP3K1 and breast cancer.