May play a role in innate immunity in mouth, nose and lungs. Binds bacterial lipopolysaccharide (LPS) and modulates the cellular responses to LPS. May be involved in formation of the left-right axis in the node of the developing embryo. Expressed in tongue, lung, thymus, and stomach. Expressed in epithelia of palate, anterior pharynx, trachea and upper bronchi. Expressed in distal tip of papillae in the anterior third of the tongue and in serous cells of von Ebner glands in the posterior third of the tongue. Expressed in columnar epithelium of the duodenum in embryonic gut at 16.5 dpc. Detectable in crown cells of the embryonic node from 7.5 dpc. Initial uniform expression develops asymmetrically with a higher level on the left side of the node until expression disappears around 13.5 dpc. Expressed in antrum pyloricum of the stomach from 11.5 dpc to 16.5 dpc and in dorsal tongue epithelium from 14.5 dpc to 16.5 dpc. Asymmetric expression in the embryonic node is dependent on Invs and Dnahc11. Belongs to the BPI/LBP/Plunc superfamily. Plunc family.