SIRT1 and malignant peripheral nerve sheath tumor: This report has shown that 29 of 49 (64%) cases of leiomyosarcoma expressed cytoplasmic SIRT1 but could not detect SIRT1 expression in 7 synovial sarcoma, 5 liposarcoma, 4 Ewing sarcoma, 4 malignant peripheral nerve sheath tumor, 4 undifferentiated pleomorphic sarcoma, and 4 clear cell sarcoma [19].