MDM2 and neoplasm: When amplified, MDM2 facilitates proteasomal degradation of p53, which promotes tumorigenesis.1-3MDM2 amplification has been reported in multiple tumor types4-6 and is a hallmark of tumorigenesis.3 In certain tumor types, such as glioblastoma and well-differentiated liposarcoma, MDM2 amplification and TP53 alterations are mutually exclusive,4,5 which is consistent with the inhibitory function of MDM2.