PRRT2 and Ewing sarcoma: Weak PKCθ expression was reported by other researchers in 25-33% of leiomyomas, 6-28% of leiomyosarcomas, 33% of malignant peripheral nerve sheath tumors/Ewing sarcomas, 10-57% of gastrointestinal schwannomas (especially in Verocay bodies), 15% of desmoid tumors, more than one-third of melanomas and 10% of adenoid cystic carcinomas [6, 7, 9, 15, 19, 20].