We compared the co-migrating nature of MDM2-C and MDM2-FL using the variable immunoreactivity of human cancer cell extracts probed with MDM2 C410 polyclonal antibody (for detection of MDM2-C) to the same extracts probed with the MDM2 pan-reactive mouse monoclonal 4B11 antibody (for the detection of MDM2-C and MDM2-FL). This evidence concerns the gene MDM2 and cancer.