AQP4 and autoimmune optic neuritis: They proposed a new classification of autoimmune optic neuritis, including MS-associated optic neuritis (MS-ON), AQP4 antibody–associated optic neuritis (AQP4-ON), MOG antibody–associated optic neuritis (MOG-ON), and CRMP5 antibody–associated optic neuritis (CRMP5-ON).