Multiple previous studies have shown that virtually all malignant rhabdoid tumors [33] and poorly-differentiated chordomas [34], 90% of epithelioid sarcomas [35, 36], as well as a subset of epithelioid malignant peripheral nerve sheath tumors [30, 31], myoepithelial carcinomas [35] and extraskeletal myxoid chondrosarcomas [37] demonstrate SMARCB1 inactivation and/or loss either by FISH or IHC. This evidence concerns the gene SMARCB1 and malignant peripheral nerve sheath tumor.