To visualize this new inhibitor functional effect on CFTR activity,a N-terminally fluorosceinated analogue of 40 (F*-40) was synthesized for Ussing Chamber assays.The treatment of CFBE bronchial epithelial cells from CF patientsexpressing F508del-CFTR with F*-40 increasedthe half-life and the amount of apical F508del-CFTR channels, andthis CFTR rescue effect was magnified when 40 was combinedwith the first-generation corrector 5. Here, CFTR is linked to cystic fibrosis.