Butyrylcholinesterase (BChE) is a serum and tissue-resident esterase with broad substrate specificity that primarily functions in detoxifying xenobiotic esters 1. The enzyme catabolizes acetylcholine and various ester-containing drugs and prodrugs, with over two dozen marketed drugs serving as substrates 2. Beyond drug metabolism, BChE displays physiological importance in hydrolyzing ghrelin, the 'hunger hormone,' thereby regulating circulating ghrelin levels and affecting weight gain, fat metabolism, and behavioral traits like aggression 3. Additionally, BChE acts as a bioscavenger protecting against neurotoxic organophosphate compounds by metabolizing them before they reach acetylcholinesterase in the nervous system 4. Clinically, BChE deficiency, caused by over 70 mutations in the BCHE gene, is notable primarily for heightened sensitivity to myorelaxant drugs succinylcholine and mivacurium, with genetic variants like rs1799807 frequently associated with prolonged apnea 1. The atypical K-variant (rs1803274) shows significant associations with xenobiotic exposure and inflammatory responses in occupational settings 5. Importantly, individuals with complete BChE deficiency appear asymptomatic otherwise, suggesting redundancy in acetylcholine metabolism 1. Recent studies demonstrate that plasma BChE activity correlates with longevity in cardiovascular disease patients 3, highlighting emerging clinical significance beyond traditional pharmacological roles.