Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disease of the central nervous system and predominantly involves the optic nerve and spinal cord, causing blindness and paralysis.1 The major pathogenic antibody of NMOSD is aquaporin-4 antibody (AQP4-Ab), while myelin oligodendrocyte glycoprotein antibody (MOG-Ab) is found in some patients with NMOSD who do not have AQP4-Ab.2,3. Here, AQP4 is linked to neuromyelitis optica.