Anti-Synovial Sarcoma, X breakpoint 4 antibodies are used in antigen-specific immunodetection in biological samples. The target Synovial Sarcoma, X breakpoint 4 is a known alias name of the protein SSX family member 4, encoded by the SSX4 gene in humans. It is reported to be expressed in the testis. Other synonyms for Synovial Sarcoma, X breakpoint 4 include CT5.4, protein SSX4, and cancer/testis antigen 5.4.