A number of genes, such as ABCC2, BUBR1, CCND2, CCND3, CCNDE2, GREB1, MKI67, TK2, CDKN1A, TOP2A and TOP2B used this tool to validate or confirm the prognostic power in breast cancer [25–31, 38] and/or lung cancer [35]. This evidence concerns the gene TK2 and breast cancer.