Has bactericidal activity. May act as a ligand for C-C chemokine receptor CCR6. Positively regulates the sperm motility and bactericidal activity in a CCR6-dependent manner. Binds to CCR6 and triggers Ca2+ mobilization in the sperm which is important for its motility. Monomer. Homodimer. Associates with tumor cell membrane-derived microvesicles. Belongs to the beta-defensin family.