The overexpression of MDM2 results in an increase in the rate of p53 degradation, and, consequently, a reduction in its levels, preventing it from performing its antitumor functions and increasing the risk of tumor development [7], as confirmed in a study in which there was a 100% incidence of tumorigenesis in MDM2-transgenic mice containing multiple copies of the MDM2 transgene inserted into a single site within the genome [62]. The gene discussed is MDM2; the disease is neoplasm.