AQP4 and neuromyelitis optica: With regard to our mouse model of NMO produced by passive, intracerebral transfer of AQP4-IgG, though it recapitulates the major pathological features of human NMO, it is far from the ideal, not yet realized model of NMO in which spontaneous AQP4 autoimmunity produces NMO pathology in spinal cord, optic nerve and brain.