18), resulting in either the SYT-SSX1 or SYT-SSX2 gene fusion.     ///    Approximately two thirds of the tumors had an SYT-SSX1 and one third had an SYT-SSX2 fusion transcript.     ///    "Tumors with SYT-SSX2 had a significantly higher mean and median Ki-67 labeling index than those with SYT-SSX1, but a comparison of Ki-67 according to fusion type, histologic type, and sample source suggested that the main determinants of proliferation rate were the latter two factors. "    ///    "All biphasic synovial sarcomas had the SYT-SSX1 fusion, whereas all tumors with SYT-SSX2 were of monophasic morphology. "