DEFB118 is a member of the beta subfamily of defensins. Beta-defensins are antimicrobial peptides that protect tissues and organs from infection by a variety of microorganisms. Expression of this gene is regulated by androgen, and the encoded protein binds to sperm and exhibits antibacterial activity. This protein is found in a cluster with other beta-defensin genes on the long arm of chromosome 20. Recombinant human DEFB118 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.