TP53 and cancer: Promotion of cancer cell proliferation and inhibition of apoptosis by O-GlcNAcylation is further supported by OGT-mediated O-GlcNAcylation and stabilization of the polycomb group transcription repressor Bmi-1, which inhibits transcription of p53, PTEN, and CDKN1A/CDKN2A genes and prevents their tumor suppressive activities (192).