In a large series of 514 human sarcomas including undifferentiated pleomorphic sarcomas, rhabdomyosarcoma, synovial sarcomas, adult fibrosarcoma/spindle cell sarcoma and leiomyosarcomas, more than half of the tumours displayed endosialin on neoplastic sarcoma cells, whereas, in the remaining cases endosialin expression was restricted to pericytes and stromal fibroblasts [9]. The gene discussed is CD248; the disease is synovial sarcoma.