Given the growing recognition of p53-independent, pro-oncogenic MDM2/MDMX signaling, we sought to investigate the anti-proliferative consequence of disrupting MDM2 dimerization against a panel of TP53 WT and MT human cancer cell lines from a broad range of cancer lineages (solid and hematological, Figures 3A and 3B). This evidence concerns the gene MDM4 and cancer.