IL17A and cystic fibrosis: However, IL-17/TNFα have been recently shown to produce hyperviscosity, affecting mucociliary clearance [237], and other studies have reported that the inflammatory mediator TGF-β decreases the CFTR function in the airway cells of non-CF subjects [238] and CFTR biogenesis [239], and negatively affects F508del CFTR rescue [239].