Serum anti-aquaporin-4 antibody 1:320 [(0) (AQP4-Ab; AQP4-Ab was detected by indirect immunofluorescence staining using human AQP4 transfected HEK 293 cells, by a cellbased assay; CBA), This had been recommended in International consensus diagnostic criteria for neuromyelitis optica spectrum disorders)] (Fig. 1). This evidence concerns the gene AQP4 and neuromyelitis optica.