CFTR is abundantly expressed in epithelial cell membranes and, as such, CF disease particularly affects epithelial sites: the submucosal glands, airway surface epithelium [40], pancreatic ductal epithelium, the epithelium of the crypts of Lieberkuhn throughout the gastrointestinal tract [41], the epithelium of sweat glands [42], the epithelium of the developing genital ducts, adult epididymis and vas deferens, and the cervical and the uterine epithelial surfaces [43, 44]. Here, CFTR is linked to cystic fibrosis.