Subgroup analyses for breast cancer (BRCA1/BRCA2) and colorectal cancer (MLH1/MSH2/MSH6) were also significant, with relative risks of family history of 1.72 (95% CI 1.34–2.20) and 1.93 (95% CI 1.13–3.27) respectively. This evidence concerns the gene BRCA1 and breast cancer.