In addition, ancillary tests for MDM2 overexpression or MDM2 amplification aid in distinction.34,35 Uncoupling protein 1 (UCP-1) is a recently described protein transporter and is considered a sensitive and specific marker of brown fat differentiation when compared to white/abdominal fat.36 Further, Kojima et al tested UCP-1 on their cohort of liposarcomas with brown fat differentiation and found that UCP-1 is expressed in these foci,35 which could be very useful to confirm brown fat differentiation when needed. This evidence concerns the gene MDM2 and liposarcoma.