TNFSF13B and immunoglobulin G4-related sclerosing disease: It has been found that serum BAFF levels in patients with IgG4-RD were significantly elevated, while glucocorticoid therapy could dramatically reduce the levels of serum BAFF and IgG4.[8] It has also observed in a patient with Sjogren's syndrome complicated with cryoglobulinemic vasculitis and elevated serum BAFF levels that serum cryoglobulins continuously turned negative after treatment with belimumab (a BAFF blocker).[9] So, the hypothesis put forward by Kimaya et al[4] deserves attention and should be further studied and verified in the future.