 ApoD is 169 amino acids long, including a secretion peptide signal of 20 amino acids.It contains two glycosylation sites (aspargines 45 and 78) and the molecular weight of the mature protein varies from 20 to 32 kDa (see figure 1).The resolved tertiary structure shows that ApoD is composed of 8 anti-parallel β-strands forming a hydrophobic cavity capable of receiving different ligands.