SMA, which was consistently negative in our NST caseload, is expressed in myofilaments of smooth muscle cells, myofibroblasts and pericytes and has been reported in PWT, leiomyosarcomas, chondrogenic tumors, rhabdomyosarcomas, melanomas, basal cell carcinomas and other tumor types [2,26]. This evidence concerns the gene SMN1 and rhabdomyosarcoma.