In cancers with intact TP53 gene, the functional protein is inactivated by overexpressed mouse double minute 2 (MDM2) and/or MDM4 which bind to the N-terminal domain and inhibit the transcriptional function of p53, or promote p53 mono- and/or polyubiquitination and nuclear export and proteasomal degradation [33]. This evidence concerns the gene MDM2 and cancer.