CDK2 and breast cancer: However, for each of genes including CCNE1 (a gene encoding cyclin E1 protein, formerly called cyclin E) and CDK2, they only evaluated the association of the selected individual SNPs or combination of them with risk or survival of cancers such as BC, lung cancer, endometrial cancer and ovary cancer [21]–[28], which couldn't capture the whole contribution of a gene to the development and progression of a particular cancer.