The following mammalian lipid-binding serum glycoproteins belong to the same family [1,2,3]:

• Lipopolysaccharide-binding protein (LBP). LBP binds to the lipid A moiety of bacterial lipopolysaccharides (LPS), a glycolipid present in the outer membrane of all Gram-negative bacteria. The LBP/LPS complex seems to interact with the CD14 receptor and may be responsible for the secretion of α-TNF.
• Bactericidal permeability-increasing protein (BPI). Like LBP, BPI binds LPS and has a cytotoxic activity on Gram-negative bacteria.
• Cholesteryl ester transfer protein (CETP). CETP is involved in the transfer of insoluble cholesteryl esters in reverse cholesterol transport.
• Phospholipid transfer protein (PLTP). May play a key role in extracellular phospholipid transport and modulation of HDL particles.

These proteins are structurally related and share many regions of sequence similarities. As a signature pattern we have selected one of these regions, which is located in the N-terminal section of these proteins; a region which could be involved in the binding to the lipids [2].