Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory autoimmune disease primarily mediated by Aquaporin-4 (AQP4) antibodies [1], that preferentially affects AQP4-riched regions such as the optic nerve, spinal cord, area postrema (AP), brainstem and diencephalon. This evidence concerns the gene AQP4 and neuromyelitis optica.