MDM2 and liposarcoma: Using the combination of MDM2, CDK4 and p16 is helpful in distinguishing well-differentiated liposarcoma from lipoma, and it had been suggested that the use of fluorescence in situ hybridization (FISH) to access MDM2 gene amplification is more sensitive and specific than immunohistochemistry in distinguishing well-differentiated liposarcoma from lipoma [10].