CFTR and cystic fibrosis: In the second series of experiments, we investigated if the treatment of polarized human bronchial primary epithelial cells from CF patients (CF-HBE) cultured in air–liquid conditions with either 407882 or 118208 (1 μM for 24 h) leads to functional correction of ΔF508-CFTR by short-circuit current experiments (Isc).