A CFTR potentiator (Ivacaftor, Kalydeco, Vertex Pharmaceutical) is available for a small fraction (5%) of CF patients bearing class III mutations (such as the G551D membrane-resident channel-dead CFTR mutant).26 Moreover, for the majority (>70%) of patients bearing the most common CFTR mutation, F508del-CFTR, the FDA approved the combination of the CFTR potentiator Ivacaftor with the corrector Lumacaftor (Orkambi), although this therapy is only marginally effective.27, 28, 29, 30, 31. This evidence concerns the gene CFTR and cystic fibrosis.