ADRA1A encodes the alpha-1A adrenergic receptor, a G protein-coupled receptor that binds catecholamines norepinephrine and epinephrine to activate phospholipase C and calcium signaling pathways. The receptor plays critical roles in cardiovascular physiology, including regulation of cardiac hypertrophy and blood pressure control. In cardiac tissue, ADRA1A expression inversely correlates with hypertrophy severity - decreased expression enhances cardiac hypertrophy in pregnancy-associated hypertensive mice 1, while the receptor cooperatively regulates hypertensive heart disease with miR-19b and miR-16 2. Beyond cardiovascular function, ADRA1A demonstrates broader physiological roles, including sympathetic regulation of lacrimal gland tear secretion where its activation reduces tear production and contributes to dry eye pathology 3. The gene shows significant disease associations through both genetic and epigenetic mechanisms. Polymorphisms in ADRA1A associate with metabolic syndrome severity 45 and autoantibody production in hypertensive patients 6. Epigenetic alterations include promoter hypermethylation in hepatocellular carcinoma, where decreased ADRA1A expression may contribute to tumorigenesis 7, and in opioid use disorder 8, suggesting broader roles in addiction and cancer pathways.