High Quality Content by WIKIPEDIA articles! Apolipoprotein E (ApoE) is a class of apolipoprotein found in the chylomicron and Intermediate-density lipoprotein (IDLs) that is essential for the normal catabolism of triglyceride-rich lipoprotein constituents.. It is synthesized in various organs, with highest expression in liver cells and in the central nervous system. It binds to receptors of the low density lipoprotein receptor gene family.