AQP-4 is one of the most valuable tools for the diagnosis of NMO (Lennon et al., 2004), and a novel potential therapeutic approach using a recombinant monoclonal anti-AQP4 antibody that selectively inhibits NMO-IgG binding to AQP-4 has been proposed (Tradtrantip et al., 2012). This evidence concerns the gene AQP4 and neuromyelitis optica.