MDM2 and alveolar soft part sarcoma: Recurrent alterations identified were often unique to specific sarcoma subtypes; CDK4/MDM2 amplifications were identified in all but one dedifferentiated liposarcoma, ASPSCR1-TFE3 fusions in all patients with alveolar soft part sarcoma, and fusions involving EWSR1 in all patients with SBRCT.