CFTR and cystic fibrosis: This goal was first met with the introduction of the CFTR-potentiator ivacaftor (IVA), which efficiently enhanced CFTR channel gating in the small group of CF patients with CFTR gating mutations (Ramsey et al., 2011) and achieved substantial improvements in nutritional status and pulmonary function (De Boeck et al., 2014; McKone et al., 2014).