It is characterized by the typical translocation t(X;18)(p11;q11) that generates the fusion between the synovial sarcoma translocation, chromosome 18 (SS18 or SYT) gene on chromosome 18 and either synovial sarcoma, X breakpoint 1, 2 or 4 (SSX1, SSX2 or SSX4) genes on the X chromosome [33]. The gene discussed is SSX1; the disease is synovial sarcoma.