The KIR4.1 study in MS autoimmune pathogenesis drew an interesting comparison to the role of a water channel, AQP4, as an important autoimmune target in another inflammatory demyelinating disease, NMO (Lennon et al., 2004; Waters and Vincent, 2008; Hinson et al., 2012). The gene discussed is KCNJ10; the disease is neuromyelitis optica.