In diabetes, hyperglycemia induces overactivity of the hexosylamine biosynthesis pathway (HBP), leading to increased synthesis of UDP-N-acetyl-d-glucosamine, a substrate that O-linked N-acetylglucosamine (GlcNAc) transferase (OGT) uses to O-GlcNAcylate the target protein [6]. This evidence concerns the gene OGT and diabetes mellitus.