März et al. showed [25] that the A allele at c.−30G>A of GCK was associated with an increased risk of coronary artery disease in not only patients with type 2 diabetes but also individuals who did not have diabetes, albeit with a much weaker association (OR = 1.27; 95% CI 1.02–1.59). Here, GCK is linked to type 2 diabetes mellitus.