Rather, negative OCB and negative AIs are frequent findings in antibody-related autoimmune disorders of the CNS, including MOG-IgG-positive encephalomyelitis [45–49] and AQP4-IgG-positive neuromyelitis optica spectrum disorders [44, 50], two diseases in which a direct pathogenic impact of the antibody has been proven or is highly likely [51–54]. This evidence concerns the gene AQP4 and neuromyelitis optica.