RB1 and sarcoma: The p53 tumor suppressor pathway (TP53, MDM2, MDM4) and Rb pathway, including associated canonical cell cycle genes (RB1, CDKN2A/B, CDK4/6, CCND1/2/3, CCNE1), were altered in 47.8% and 46.8% of all sarcomas, respectively30–32.