As noted above, this is the first study to investigate the role of genetic variants in IGF signaling as modifiers of breast cancer risk in women who carry deleterious mutations in BRCA1 and BRCA2. While the study does provide an important first step in identifying potential genetic modifiers of risk among BRCA1 and BRCA2 carriers, it does suffer some limitations. This evidence concerns the gene BRCA2 and breast carcinoma.