Interleukin 7 receptor (IL7R) is a transmembrane receptor that belongs to the typeⅠcytokine receptor fami-ly. It consists of the cytokine-specific α-chain (IL7Rα, CD127) and the shared common cytokine γ-chain (γc, CD132). IL-7R is expressed in various cell types, including lymphoid precursor cells, pro-B cells, T cells, thymocytes, dendritic cells, myeloid cells and monocytes. Under physiological conditions, IL7R is a vital cytokine for development and survival of T and B cells. IL7R plays a key role in the pathogenesis of multiple sclerosis (MS). Single nucleotide polymorphisms (SNPs) in the gene encoding IL7Rαhave emerged through genetic studies of MS patients. In experimental autoimmune encephalomy-elitis (EAE) mouse model of MS, treatment with neutralizing anti-IL7Rαantibody results in significant improvement of EAE. Therefore, IL7R may serve as a novel target for MS therapies.