The present study found that in patients with SS + PBC, the levels of IgG3, IgG3/IgG, IgG2, and IgG2/IgG were higher compared to those in patients with SS; however, the levels of IgG1/IgG were lower in patients with SS + PBC than those in patients with SS. The gene discussed is IGHG3; the disease is synovial sarcoma.