APOA4 (apolipoprotein A-IV) is a component of HDL and chylomicrons. Its primary site of synthesis is the intestine, in association with lymph chylomicron particles. Although its precise function is not known, APOA4 is a potent activator of lecithin-cholesterol acyltransferase (LCAT) in vitro. In rodents, Apo A-IV inhibits gastric emptying and serves as a satiety factor whose synthesis and secretion are increased by the ingestion of dietary fat. It also possesses anti-inflammatory and antiatherogenic properties