Has a salt-sensitive antimicrobial activity against Gram-negative bacteria, including E.coli, Gram-positive, including S.aureus, and fungi, including C.albicans. Binds to and neutralizes bacterial lipopolysaccharides (LPS), abolishing TNF production by macrophages challenged with LPS. Rescues the LPS-induced reduction of sperm motility in vitro and may protect from LPS-induced lethality. Expressed in epididymis, predominantly in the caput (at protein level). Belongs to the beta-defensin family.