FCGR2B and systemic lupus erythematosus: In fact, blockade of activating FcγR and/or enhanced inhibitory FcγRIIB are underlying mechanisms of intravenous Igs currently used as first‐line or adjunct therapy in autoimmune and immunodeficient diseases61; vasculoprotective effects, including aortic aneurysm reduction, has been reported in many cases (eg, Kawasaki disease and systemic lupus erythematosus).62