The beta defensins are antimicrobial peptides implicated in the resistance of epithelial surfaces to microbial colonisation [1].

1: hBD-1: a novel beta-defensin from human plasma. Bensch KW, Raida M, Magert HJ, Schulz-Knappe P, Forssmann WG; FEBS Lett 1995;368:331-335. PMID:7628632

2: The human beta-defensin-1 and alpha-defensins are encoded by adjacent genes: two peptide families with differing disulfide topology share a common ancestry. Liu L, Zhao C, Heng HH, Ganz T; Genomics 1997;43:316-320. PMID:9268634