The genes for the lipopolysaccharide binding protein (LBP) and the bactericidal permeability increasing protein (BPI) are encoded in the same region of human chromosome 20.

The lipopolysaccharide binding protein is an acute-phase reactant produced during gram-negative bacterial infections. The bactericidal/permeability increasing protein is associated with human neutrophil granules and has bactericidal activity on gram-negative organisms. In addition to their functional relationship, both proteins share extensive structural similarity. This article demonstrates that the genes for both proteins are in the same region of human chromosome 20, between q11.23 and q12.