CFTR and cystic fibrosis: Cystic fibrosis (CF) is a genetic disorder caused by mutations to the cystic fibrosis transmembrane conductance regulator (CFTR) gene (Kerem et al., 1989; Riordan et al., 1989; Rommens et al., 1989), which in turn leads to reduced or absent CFTR protein function to move anions across the surface of the epithelium (Poulsen et al., 1994).