Genotyping of 42,671 invasive breast cancer cases and 42,164 controls from BCAC found evidence that both CHEK2 c.349A>G and c.538C>T were associated with increased breast cancer risk; OR 2.26 (95% CI, 1.29–3.95) and OR 1.33 (95% CI, 1.05–1.67) respectively [19]. This evidence concerns the gene CHEK2 and breast cancer.