Consistent with this finding, 40% of patients with CDKN2A/CDK4 alteration had de-differentiated liposarcoma (26.7% LMS, 20% UPS, and 13.3% osteosarcoma), while 83.3% of patients with a Rb1 alteration had leiomyosarcoma. The gene discussed is RB1; the disease is undifferentiated pleomorphic sarcoma.