ATRX and osteosarcoma: ATRX was the most frequently altered DDR gene (10.1% overall), with mutations observed across 24 sarcoma subtypes (11 subtypes with >10% mutation rate including perivascular epithelioid cell tumor, uterine sarcoma other, angiosarcoma, leiomyosarcoma, mesenchymal chondrosarcoma, pleomorphic sarcoma, epithelioid sarcoma, sarcoma NOS, osteosarcoma, spindle cell sarcoma, and fibrosarcoma.