With the introduction of new anti-diabetic medications such as dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, and sodium-glucose transport protein 2 (SGLT-2) inhibitors, diabetes management has improved and a targeted HbA1c < 7.0% has become more achievable (1, 3, 25, 42–48). This evidence concerns the gene GCG and diabetes mellitus.