Therefore, a deficiency of CFTR Cl− channels causes: (1) infection of bacteria and viruses due to dehydration and high glucose contents at the airway apical surface, associated with a relatively high permeability of the paracellular pathway, and (2) a decrease in insulin secretion due to the diminution of glucose-induced membrane depolarization caused by a lack of Cl− efflux through CFTR Cl− channels at the plasma membrane of pancreatic β cells. This evidence concerns the gene CFTR and infection.