TP53 and liposarcoma: In retroperitoneal localization, MDM2 amplifications and p53 mutations are mutually exclusive, but in non-retroperitoneal localizations of dedifferentiated liposarcoma, TP53 mutations appear in the presence of MDM2 amplification.[17] The MDM2-p53 axis is regulated by multiple oncogenic signaling pathways involved in sarcomogenesis and represents a possible therapeutic target.