Glucagon-like peptide 1 (GLP-1) improves endothelial function in diabetes [7–9], so therapeutic strategies for patients with T2DM are focused in increasing the incretin response, either by inhibiting dipeptidyl peptidase-4 (DPP-4) activity or by using degradation-resistant GLP-1 analogues [7]. This evidence concerns the gene GCG and diabetes mellitus.