Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disease of the central nervous system (CNS) characterized by the generation of autoantibodies against aquaporin-4 (AQP4), which is the most abundant water channel in the CNS [1], severe immune-mediated demyelination, and axonal damage that preferentially targets the optic nerves and spinal cord [2]. Here, AQP4 is linked to neuromyelitis optica.