ENaC is functionally coupled with cystic fibrosis transmembrane conductance regulator (CFTR) [89,90]; in cystic fibrosis (CF), the absence of CFTR at the plasma membrane leads to an overactivation of ENaC and consequently excessive Na+/fluid absorption contributing to airway surface dehydration and impaired mucociliary clearance of CF airways. This evidence concerns the gene CFTR and cystic fibrosis.