Water secretion and embryological layers in cystic fibrosis

Cystic fibrosis primarily affects tissues containing secretory epithelia, but not all of them become diseased. The distribution of clinical disease corresponds closely to the effect on net anion-linked water secretion, which is reduced across epithelia of endodermal and mesodermal origin but not those of ectodermal origin. Although the gene is expressed in all secretory epithelia, its effects on water secretion are bypassed in those of ectodermal origin.