Many of the associations, such as PER3 (rs1012477), CSNK1E (rs1534891) and CLOCK (rs11133373, rs3749474), are novel in relation to breast risk but may not be specific to breast cancer, because they have also been found to be associated with prostate and colorectal cancer risk [47,51]. This evidence concerns the gene CSNK1E and colorectal cancer.