RTN4 and multiple sclerosis: Abbreviations: MS (multiple sclerosis), Nogo-A (neurite outgrowth inhibitor A), EAE (experimental autoimmune encephalomyelitis), LINGO-1 (leucine-rich repeat and immunoglobulin-like domain-containing Nogo receptor-interacting protein 1), CUP (cuprizone), H1 (histamine receptor 1), M1 (muscarinic acetylcholine receptor 1), M3 (muscarinic acetylcholine receptor 3), OPC (oligodendrocyte precursor cell), Sob-AM2 (sobetirome-AM2), SEMA4D (semaphorin 4D), α2 (alpha-2 adrenergic receptor), and MEK (mitogen-activated protein kinase kinase).