May play a role in innate immunity in mouth, nose and lungs. Binds bacterial lipopolysaccharide (LPS) and modulates the cellular responses to LPS. Detected in duodenum mucosal crypts of cholera patients, near Paneth cells (at protein level). Detected in trachea, nasal septal epithelium and lung. Belongs to the BPI/LBP/Plunc superfamily. Plunc family.