Variants in this region have previously been linked to several aspects of IL-2R signalling in T1D and MS patients [27] and the MS-associated variants we identify (whether under the M1 or M2 models) all showed some evidence of association with expression of CD25 on the surface of T cells, linking IL2RA in a primary way into the etiology of this disease. Here, IL2RA is linked to type 1 diabetes mellitus.