Longitudinally extensive myelitis is a classic finding in various pathologies such as neuromyelitis optica syndrome disorders (NMOSD), either mediated by myelin-oligodendrocyte glycoprotein antibody (MOGAD) or aquaporine-4 antibody (AQP4+), neurosarcoidosis, anti-glial fibrillary protein (GFAP) encephalomyelitis, infectious myelitis, or connective tissue diseases [7,8,9,10]. The gene discussed is AQP4; the disease is myelitis.