Background：Defensins are cysteine-rich cationic polypeptides that are important in the immunologic response to invading microorganisms. The protein encoded by this gene is secreted and is a member of the beta defensin protein family. This protein binds spermatozoa and has antimicrobial activity against E. coli. Beta defensin genes are found in several clusters throughout the genome, with this gene mapping to a cluster at 20p13.
