CFTR and cystic fibrosis: Cystic fibrosis (CF) is an autosomal recessive disorder caused by the alteration of a gene located on the long arm of chromosome 7 that encodes for a protein of 1480 amino acids, the cystic fibrosis transmembrane conductance regulator (CFTR), which functions as a chloride channel on the apical membrane of epithelial cells [1].