The SSX genes are normally expressed in the testis and thyroid, and these genes are also expressed in numerous types of human cancers including melanoma [38–40], multiple myeloma [41, 42], non-Hodgkin's lymphoma [39], neuroblastoma [43], brain tumors [39, 44], various carcinomas of different origin [39, 45–51], and several types of sarcomas (synovial sarcoma, osteosarcoma, and malignant fibrous histiocytoma) [39, 52–57]. This evidence concerns the gene SSX2 and synovial sarcoma.