This gene encodes a lipid-binding protein belonging to the apolipoprotein gene family. The protein is thought to play a role in lipid metabolism. Polymorphisms in this gene may influence circulating lipid levels and may be associated with coronary artery disease risk. This gene is present in a cluster with other related apolipoprotein genes on chromosome 19. Naturally occurring read-through transcription exists between this gene and the neighboring downstream apolipoprotein C-II (APOC2) gene.