Except for the improvement of clinical manifestations, patients’ serum levels of IgG, IgG4, IgA, IgM, ESR and IgE were all decreased at treatment, consistent with the study of iguratimod in the treatment of RA.21, 26 Further, plasma IFN‐γ and BAFF was also decreased after treatment. The gene discussed is TNFSF13B; the disease is rheumatoid arthritis.