For example, the peptide antibiotics human β-defensin 1 (hBD-1) and β-defensin 2 (hBD-2), which are involved in the pathogenesis of cystic fibrosis, exhibit a same sensitivity to salt and can be inactivated in the high salt environment of the cystic fibrosis airway surface (Bals et al., 1998). This evidence concerns the gene DEFB1 and cystic fibrosis.