SMARCB1 mutations have been detected in rhabdomyoma, familial schwannomatosis, small cell hepatic fibroblastoma, skeletal extracellular myxoid chondrosarcoma, undifferentiated sarcoma, epithelial sarcoma, meningiomas and poorly differentiated chordomas. The gene discussed is SMARCB1; the disease is undifferentiated (embryonal) sarcoma.