HNF4A and diabetes mellitus: Using a relatively modest sample size (5,561 cases and 14,458 controls in the discovery step) five additional novel T2D loci were discovered [92]: HNF4A, involved in monogenic forms of diabetes and associated with β-cell development [125]; GRB14 which is associated with obesity and insulin resistance [126]; and another three loci with less clear functions; AP3S2, ST6GAL1 and VPS26A [92].