Has antibacterial activity (PubMed:12600824). Acts as a ligand for C-C chemokine receptor CCR2 (PubMed:23938203). Monomer (PubMed:23938203). Interacts with CCR2 (via extracellular N-terminal region); this interaction may preferentially require specific tyrosine sulfation on CCR2 (PubMed:23938203). Associates with tumor cell membrane-derived microvesicles (PubMed:23938203). Expressed specifically in epididymis and lung. Belongs to the beta-defensin family.