From these results, we noted that SSA/SSB and SS was more common in the RON group (SSA/SSB 23 (30.26%) and SS 11 (14.47%)), and there was a higher frequency of AQP4 antibodies, 10 (13.16%) in the RON group than in the other groups. This evidence concerns the gene AQP4 and synovial sarcoma.