 As such, the respiratory complications in cystic fibrosis are not solely caused by the lack of chloride secretion but instead by the increase in sodium and water reabsorption.This results in the deposition of thick, dehydrated mucus, which collects in the respiratory tract, interfering with gas exchange and allowing for the collection of bacteria.Nevertheless, an upregulation of CFTR does not correct the influence of high-activity ENaC.