PLUNC is the human homolog of murine plunc, and like the mouse gene, is specifically expressed in the upper airways and nasopharyngeal regions. The exact biological function of this gene is not known, however, it has been suggested to be involved in inflammatory responses to irritants in the upper airways. It 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 two is known.The cDNA encodes a leucine-rich protein of 256 amino acids that is 72% identical to the murine protein. within the human PLUNC family, amino acid sequence identity is low, ranging from 16 to 28%.