O-GlcNAc transferase (OGT) is an enzyme that catalyzes the addition of O-linked N-acetylglucosamine (O-GlcNAc) post-translational modifications to serine and threonine residues of nuclear, cytoplasmic, and mitochondrial proteins. This modification plays a crucial role in various cellular processes, including gene expression, signal transduction, and protein stability. Dysregulation of OGT has been linked to several diseases, including cancer, diabetes, and neurodegenerative disorders. Research in this area focuses on understanding the molecular mechanisms of OGT function, its role in disease pathology, and the development of therapeutic interventions targeting OGT activity.