CFTR and cystic fibrosis: Cystic fibrosis (CF) is an inherited disorder caused by mutations in the gene that codes for the CF transmembrane conductance regulator (CFTR) protein, which results in the malfunction of the CFTR protein.1 The dysfunction of the CFTR protein leads to the development and accumulation of thick mucus, particularly in the lungs, which greatly restricts mucociliary clearance.