GCK and type 2 diabetes mellitus: Vaxillaire et al. showed that the GCK −30A allele is a true risk factor for the development of both IFG and type 2 diabetes, suggesting that this allele has a significant impact on β-cell function impairment23, which is consistent with our findings regarding rs1799884 in GCK. In the present study, only rs1260326 was detected on the Korean chip (K-CHIP) and was markedly associated with the risk of IFG and type 2 diabetes.