Defensins are a family of small cationic, antibiotic peptides that contain six cysteines in
disulfide linkage. The peptides are abundant in phagocytes and small intestinal mucosa of
humans and other mammals and in the hemolymph of insects. They contribute to host
defense against microbes and may participate in tissue inflammation and endocrine
regulation during infection. Bioengineered defensins are potentially useful as prophylactic
and therapeutic agents in infections.