APOD occurs in the macromolecular complex with lecithin-cholesterol acyltransferase. It is probably involved in the transport and binding of bilin. Appears to be able to transport a variety of ligands in a number of different contexts. Homodimer. In plasma, also exists as a disulfide-linked heterodimer with APOA2. Expressed in liver, intestine, pancreas, kidney, placenta, adrenal, spleen, fetal brain tissue and tears. N-glycosylatd. N-glycan heterogeneity at Asn-65: Hex5HexNAc4 (major) and Hex6HexNAc5 (minor); at Asn-98: Hex5HexNAc4 (minor), dHex1Hex5HexNAc4 (major), dHex1Hex6HexNAc5 (minor) and dHex1Hex7HexNAc6 (minor). APOD is primarily localized in HDL (60-65%), with most of the remainder in VHDL and only trace amounts in VLDL and LDL. Belongs to the calycin superfamily. Lipocalin family.