Although there was no serologic evidence that autoantibodies target glial Kir4.1 in patients with NMO in several previous studies [41,45], it will be necessary to determine the seroprevalence of the Kir4.1 antibodies in the future, not only in patients with MS but also in patients with NMO spectrum disorders. The gene discussed is KCNJ10; the disease is neuromyelitis optica.