RB1 and neoplasm: In particular, the proliferative goals of MDM2 comprise the activation of E2 F1 transcriptional action (Kundu et al. 2017) amplified E2 F1 protein stability (Zhang et al. 2005), breakdown of the Rb-E2 F1 complex, and suppressing inhibitory effects of Rb on tumor (Miwa et al. 2006).