CD248 and synovial sarcoma: Thway et al. examined endosialin expression in 514 human soft tissue sarcomas and found that endosialin was expressed in 89% of undifferentiated pleomorphic sarcomas (104/117), 77% of fibrosarcomas (20/26), 62% of synovial sarcomas (37/60), 51% of leiomyosarcoma (94/185) and 31% of rhabdomyosarcoma (39/126).