CFTR and cystic fibrosis: However, a recent study has developed a long‐term cell culture of CF (p.Phe508del) HPAEC (Plebani et al., 2017); therefore, it would be useful to confirm the findings of the present study in cells that represent a loss of CFTR at the apical membrane (i.e., class I–II mutations; Veit et al., 2016).