STAT6 and osteosarcoma: However, nuclear staining for STAT6 has also been observed in other mesenchymal tumors such as unclassified sarcomas of spindle cell or epithelioid morphology, desmoid tumor, well-differentiated and de-differentiated liposarcoma, neurofibroma, synovial sarcoma, clear cell sarcoma, myxoid liposarcoma, alveolar soft part sarcoma, angiofibroma, angiosarcoma, DFSP, epithelioid sarcoma, fibrosarcoma, GIST, hemangioma, leiomyoma, leiomyosarcoma, low-grade fibromyxoid sarcoma, MPNST, myofibroma, myxoma, osteosarcoma and sinonasal glomangiopericytoma [40-41].