CFTR and cystic fibrosis: Cystic fibrosis (CF) is an autosomal recessive disorder caused by various mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, but the ΔF508 mutation (a deletion of the phenylalanine at amino acid position 508 in the protein) accounts for 70% of CF patients (Kerem et al., 1989).