Apolipoprotein F is predominantly associated with low density lipoprotein and functions as an inhibitory regulator of cholesteryl ester transfer protein (CETP). Apolipoprotein F, a minor apolipoprotein in human plasma, was isolated and partially characterized by Olofsson et al. (1978).

By PCR of a human hepatoma cell line cDNA library using primers based on the N-terminal sequence of purified APOF, Day et al. (1994) cloned full-length APOF. The deduced 308-amino acid proprotein has a 22-amino acid N-terminal signal peptide, and its C-terminal half contains the mature APOF peptide, which is released by proteolytic processing. The mature 162-amino acid hydrophobic APOF peptide has a calculated molecular mass of 17.4 kD and contains sites for N- and O-glycosylation.