RB1 and colorectal cancer: As an E3 ubiquitin ligase, MDM2 can ubiquitinate and degrade a variety of tumor suppressor genes, including p53, Rb, p73, and ARF, which mediate the occurrence and development of a variety of tumors, including colorectal cancer (Chaudhary et al., 2020; Lau et al., 2008; Uchida et al., 2005; Hernandez-Monge et al., 2021).