 Palate, lung and nasal epithelium carcinoma-associated protein (PLUNC) is a potential host defensive protein that is secreted from the submucosal gland to the saliva and nasal lavage fluid.PLUNC appears to be a secreted product of neutrophil granules that participates in an aspect of the inflammatory response that contributes to host defence.Short palate, lung and nasal epithelium clone 1 (SPLUNC1) may bind the lipopolysaccharide of Gram-negative nanobacteria, thereby playing an important role in the host defence of nasopharyngeal epithelium.