Cystic fibrosis (CF) is an autosomal recessive disorder caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein. A cycle of chronic, persistent infections with CF-related pathogens and an excessive inflammatory response progressively damages the airways and lung parenchyma, resulting in widespread bronchiectasis and ultimately, respiratory failure. Despite tremendous advances in understanding the CF gene and the CFTR protein, it is not known exactly how mutations in the gene and defects in CFTR lead to persistent airway infection and inflammation.