Taken together, our studies provide a molecular basis for the GLIS3 locus conferring susceptibility to type 1 (Barrett et al, 2009) and type 2 diabetes (Boesgaard et al, 2010; Dupuis et al, 2010; Liu et al, 2011), both of which involve defects in beta cell function (in the presence of insulin resistance in the case of the type 2 disease). Here, GLIS3 is linked to type 2 diabetes mellitus.