APOA4(Apolipoprotein A4) also known as ADTKD6, ApoA-IV is a 396 amino acid preprotein that plays a crucial role in lipid metabolism. After proteolytic processing, apoA-IV is secreted from the intestine in association with chylomicron particles, where apoA-IV functions as a potent activator of lecithin cholesterol acyltransferase (LCAT), an enzyme essential for the formation of cholesteryl esters in plasma. This activation is vital for the reverse transport of cholesterol, a process that helps maintain lipid homeostasis and prevent atherosclerosis. Additionally, apoA-IV is involved in regulating appetite and energy expenditure, highlighting apoA-IV′s importance in metabolic health.