At the same time, the disorder of peripheral B cell subsets exists in SS, such as the significant decrease of CD27 + memory B cells, the increase of CD27 initial B cells and CD19 + B cells (50), and the positive correlation between the number of CD19 + B cells and IgG serum level and hypergammaglobulinemia (51). The gene discussed is CD19; the disease is synovial sarcoma.