The rare genetic disease cystic fibrosis (CF) is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) functioning as a cAMP-regulated epithelial anion channel responsible for transepithelial secretion of chloride, bicarbonate and fluid that is essential for proper mucus function and effective mucociliary clearance of inhaled pathogens or irritants from the airways, thus playing an important role in mucosal defense and homeostasis of the lungs [56]. The gene discussed is CFTR; the disease is cystic fibrosis.