Neuromyelitis optica (NMO) is an autoimmune disease associated with NMO immunoglobulin G (NMO-IgG). A cure for NMO remains elusive. Researchers recently established a localized NMO rat model by injecting NMO-IgG into the spinal cord, and assessed the efficacy of anti-repulsive guidance molecule-a (RGMa) antibody in treating NMO. They found anti-RGMa antibody delayed the onset and attenuated the severity of clinical symptoms of NMO, suggesting that humanized anti-RGMa antibody is a potentially valid therapeutic approach for NMO.