MBOAT4 (membrane bound O-acyltransferase 4) is a serine O-acyltransferase that catalyzes ghrelin acylation at serine-3, preferentially using octanoyl-CoA, hexanoyl-CoA, and decanoyl-CoA as acyl donors, with C4-C12 chain length substrates being most efficient 1. This post-translational modification converts inactive des-acyl ghrelin to bioactive acyl-ghrelin, enabling its binding to the ghrelin receptor GHSR1a and subsequent metabolic effects 23. MBOAT4 is localized to the endoplasmic reticulum and Golgi apparatus and plays critical roles in energy homeostasis and glucose metabolism 4. Functionally, MBOAT4 is implicated in adipose-brain-liver communication regulating lipid metabolism and has been identified as a potential anti-obesity therapeutic target 1. MBOAT4 dysregulation associates with multiple disease states: elevated MBOAT4 expression correlates with schizophrenia pathology, potentially reflecting altered ghrelin signaling in cognition 2; elevated acyl-ghrelin and MBOAT4 expression appear neuroprotective in Alzheimer's disease 5; and MBOAT4 participates in high glucose-induced epithelial-mesenchymal transition in benign prostatic hyperplasia with type 2 diabetes 3. Genetic variants in MBOAT4 show suggestive association with anorexia nervosa etiology, consistent with ghrelin's appetite-promoting function 6.