IGHG3 and myasthenia gravis: Anti‐AChR autoantibody, mainly belonging to IgG1 and IgG3 subclasses, usually targets the main immunogenic region of AChR18 and causes MG via activation of the classical complement cascade followed by membrane lysis,19 triggering the endocytosis of AChR, and prevention of acetylcholine binding to AChR.20