TNFSF13B and autoimmune disease: In general, BlyS enhances humoral immune response by inducing the proliferation, differentiation and immunoglobulin secretion of B-lymphocytes.12 Moreover, BlyS regulates the activation and response of T cells, the over-expression of which may destroy the equilibria of cell production and autoimmune tolerance, thus triggering many types of autoimmune diseases.13 In this study, the BlyS levels of the two groups were significantly different, suggesting that the expressions of B-lymphocytes in RA patients were evidently disordered.