DEFB1 and cystic fibrosis: For example, human beta defensin-1 (hBD-1) being unable to inhibit P. aeruginosa due to a 120 mM concentration of NaCl in the lungs of cystic fibrosis patients [274] has been engineered by constructing a chimera with β-defensin-3 (hBD-3), which shows antibacterial activity also at high salt concentrations [231,232].