CA2 and immunoglobulin G4-related sclerosing disease: Others see IgG4-RD as an autoimmune disease, because anti-lactoferrin [5] and carbonic anhydrase II [6] antibodies are detected in some of IgG4-related autoimmune pancreatitis cases, and because IgG4-RD cases usually show good responses to glucocorticoid therapies.