Confocal microscopy (Fig. 3A), besides showing the expected different localisation of wt-CFTR (apical PM) and F508del-CFTR (intracellular)44, also revealed differences in the architecture of the epithelial cell cultures: while wt-CFTR cells formed a single cell monolayer, F508del-CFTR cells were multilayered, similarly to the CF lung pattern (Fig. 3A), indicative that the epithelial disorganization also occurs in airway epithelial cells expressing mutant CFTR. The gene discussed is CFTR; the disease is cystic fibrosis.