SOAT2 (sterol O-acyltransferase 2) is an endoplasmic reticulum membrane enzyme that catalyzes cholesterol esterification, playing a critical role in cholesterol homeostasis and lipid metabolism 12. The enzyme's active site is located on the luminal side of the ER, making it less accessible to certain inhibitors compared to SOAT1 3. SOAT2 functions in cholesterol metabolic processes, very-low-density lipoprotein particle assembly, and cholesterol efflux 24. In disease contexts, SOAT2 demonstrates significant clinical relevance across multiple pathological conditions. Overexpression occurs in regulatory T cells from elderly cancer patients, where it promotes cholesterol metabolism through the SREBP2-HMGCR-GGPP pathway, leading to enhanced immunosuppressive functions and reduced anti-tumor immunity 2. In hepatocellular carcinoma, SOAT2 is regulated by NSUN2-mediated RNA methylation and contributes to immune evasion and metabolic reprogramming 5. Additionally, SOAT2 is involved in acute pancreatitis pathogenesis through ferroptosis regulation 1. Clinically, SOAT2 serves as a prognostic biomarker in hepatocellular carcinoma and a potential therapeutic target, with selective inhibitors showing promise in treating acute pancreatitis 146.