A possible role of MOG-IgG antibodies in NMO-related diseases is supported by recent findings of our group, demonstrating an increased frequency of MOG-IgG in pediatric patients with recurrent ON compared to monophasic ON subjects (Rostasy K, Mader S, Schanda K, Huppke P, Gärtner J, Kraus V, Karenfort M, Tibussek D, Blaschek A, Kornek B, Leitz S, Schimmel M, Di Pauli F, Berger T, Reindl M: Anti-MOG antibodies in children with optic neuritis, in press). The gene discussed is MOG; the disease is optic neuritis.