At present, the clinical and laboratory features of NMO have been recognized by several independent studies.2,3,8 Specifically, the discovery of a specific NMO-immunoglobulin G (NMO-IgG) autoantibody against the aquaporin-4 water channel in NMO patients was confirmed by different experiments, and magnetic resonance imaging findings of NMO were in accordance with the presence of longitudinally extensive myelitis.9,10 More than that, the studies published before have suggested that both genetic and environmental factors could affect the inflammatory demyelinating disease. Here, AQP4 is linked to neuromyelitis optica.