In summary, NMO attacks are then characterized by AQP4-IgG antibody directed against water channel protein AQP4, activating the antibody/complement system, cascade and leading to the destruction of astrocytes and neuronal tissue, in which a wide range of demyelinating lesions could occur, including large necrosis.4Therefore, NMO relapses are usually more severe than MS relapses, and most NMO patients often present accumulated disability due to poor recovery from the attacks, resulting in a worse prognosis for this disorder. The gene discussed is AQP4; the disease is myeloid sarcoma.