IL6 and synovial sarcoma: As a hallmark of SS, B-cell hyperactivity causes hypergammaglobulinemia (3, 4), autoantibody production, increased serum interleukin-6 (IL-6), IL-17, IL-21, IFN-α levels, and an increased risk of lymphoma, particularly B-cell-derived non-Hodgkin lymphomas (5, 6).