Apolipoprotein A4 is a plasma protein and synthesized in the intestine and liver. Apoa4 is secreted into circulation on the surface of newly synthesized chylomicron particles. The primary functions of Apoa4 have not been clearly established; however, Apoa4 has been implicated in regulating appetite and satiety in rodent models, modulating the lipid transport in vitro, and activating lecithin-cholesterol acyltransferase and cholesterylester transfer protein in vitro.