GCK and type 2 diabetes mellitus: We previously investigated the contribution of some candidate gene variants identified through GWAS (TCF7L2, HHEX, GCK, ENPP1 and KCNJ11) to T2D in Tunisian; only TCF7L2 (rs7903146) was significantly associated with T2D in Tunisians [18], thereby demonstrating ethnic contribution of the association of specific gene variants to T2D pathogenesis.