Our prior data using mouse and rat models of NMO produced by injection of AQP4-IgG into brain or the spinal cerebrospinal space implicate a protective role for CD59 in brain and spinal cord in vivo [32, 33], which was supported by in vitro data in astrocyte cultures from knockout mice and rats or following CD59 enzymatic neutralization. Here, AQP4 is linked to neuromyelitis optica.