CFTR and cystic fibrosis: Cystic Fibrosis (CF), a life-shortening genetic disorder affecting ~90,000 individuals worldwide [1], is caused by mutations in the CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) gene [2], which encodes a cAMP-regulated chloride (Cl−) and bicarbonate (HCO3−) channel expressed at the apical plasma membrane (PM) of epithelial cells [3].