CFTR and cystic fibrosis: Moreover, AZ has been reported to reduce IL-8 in tumour necrosis factor (TNF)-α-stimulated HBE cells transfected with CFTR (IB3-1/S9) but not CF cells (IB3; F508del/W1282X) suggestive of a link between the AZ-mediated reduction of IL-8 and functional CFTR [21].