Plays a role in the innate immune response. Binds to the lipid A moiety of bacterial lipopolysaccharides (LPS), a glycolipid present in the outer membrane of all Gram-negative bacteria (PubMed:24120359, PubMed:7517398). Acts as an affinity enhancer for CD14, facilitating its association with LPS. Promotes the release of cytokines in response to bacterial lipopolysaccharide (PubMed:24120359, PubMed:7517398). {ECO:0000269|PubMed:1698311, ECO:0000269|PubMed:20133493, ECO:0000269|PubMed:24120359, ECO:0000269|PubMed:7517398, ECO:0000305|PubMed:17481951}. This is the function of Ensembl gene identifier ENSG00000129988 (LBP, lipopolysaccharide binding protein).