This gene is the human homolog of murine plunc, and like the mouse gene, is specifically expressed in the upper airways and nasopharyngeal regions. The encoded antimicrobial protein displays antibacterial activity against Gram-negative bacteria. It is thought to be involved in inflammatory responses to irritants in the upper airways and may also serve as a potential molecular marker for detection of micrometastasis in non-small-cell lung cancer. Multiple transcript variants resulting from alternative splicing in the 3' UTR have been detected, but the full-length nature of only three are known.