These data suggest that the ability of P. aeruginosa to chronically infect the lungs of patients with COPD, pneumonia, CF, and bronchiectasis is due in part to the secretion of OMV containing Cif, which inhibits CFTR-mediated chloride secretion and thus, diminishes the clearance of respiratory pathogens by the mucociliary escalator. Here, CFTR is linked to chronic obstructive pulmonary disease.