Among others, well-differentiated (ALT/WDLPS) and dedifferentiated liposarcoma (DDLPS) were associated with the amplification of MDM2 and CDK4, leiomyosarcoma (LMS) correlated to smooth muscle differentiation, undifferentiated pleomorphic sarcoma (UPS) was characterized by the lack of any differentiation line and myxofibrosarcoma (MFS) showed fibroblastic differentiation with myxoid stroma. The gene discussed is MDM2; the disease is undifferentiated pleomorphic sarcoma.