APOC2 is a lipoprotein-associated apolipoprotein that serves as a critical activator of lipoprotein lipase (LPL), the enzyme responsible for triglyceride hydrolysis in circulating lipoproteins 1. APOC2 is a component of multiple lipoprotein classes including chylomicrons, VLDL, LDL, and HDL, where it regulates lipid metabolism and redistribution among tissues 1. The protein functions as a cofactor for lipid-metabolizing enzymes and maintains lipoprotein particle structure 1. APOC2 deficiency causes severe hypertriglyceridemia and chylomicronemia syndrome, characterized by marked triglyceride elevation and chylomicron accumulation that can precipitate life-threatening pancreatitis 23. Mutations in APOC2, such as the c.86A>CC variant identified in Chinese populations, result in absent or severely reduced APOC2 protein and dramatically impaired LPL activity 3. Additionally, post-translational modifications of APOC2 influence disease outcomes; lactylation of APOC2 at lysine 70 promotes extracellular lipolysis and has been linked to immunotherapy resistance in lung cancer 4. In cerebrovascular disease, reduced blood miR-1275 levels, which normally suppress APOC2 expression, correlate with increased ischemic stroke risk, suggesting APOC2 dysregulation contributes to atherosclerotic pathology 5. Therapeutic strategies targeting APOC2, including apoC2 mimetics and lactyl-APOC2-directed antibodies, are emerging as potential treatments for triglyceridemia and immunotherapy resistance 64.