RB1 and cancer: Of these genes, nine are confirmed cancer genes (e.g. APC, IDH1, KRAS, PTEN, RB1, and TP53), thirteen have been experimentally implicated in cancer (e.g. HLA-C, IGHG1, and KCNB1), and nine have not previously been implicated in cancer (e.g. TUBBP12).