Molecular analysis carried out at Champions Oncology unveiled the existence of a SS18-SSX1 fusion in the CTG-1173 tumors, and the presence of SS18-SSX1 and SS18-SSX4 fusions in the CTG-2004 tumors, thus solidifying the categorization of the tumor type as synovial sarcoma. This evidence concerns the gene SSX4 and synovial sarcoma.