Recent cloning and sequencing of plasma phospholipid transfer protein complementary DNA revealed that phospholipid transfer protein belongs to the lipid transfer/lipopolysaccharide binding protein family that includes the cholesteryl ester transfer protein, the bactericidal permeability increasing protein and the lipopolysaccharide-binding protein. In addition to structural similarities, members of the lipid transfer/lipopolysaccharide-binding protein family might share some common functional properties, and recent studies demonstrated that phospholipid transfer protein can act in several distinct metabolic processes. In particular, the molecular transfer of phospholipids, unesterified cholesterol, alpha-tocopherol and lipopolysaccharides by phospholipid transfer protein suggests that it might be involved both in lipoprotein metabolism and in antimicrobial defence, resulting in a growing interest in this protein.