In vitro reconstitution experiments showed that polarized HAE cultures derived from mixtures of non-CF and ∆F508/∆F508 primary human airway epithelial cells at a 2:8 ratio (WT:CF) restored ∼70% of CFTR-mediated Cl−transport in 100% wild-type cultures (Farmen et al., 2005). Here, CFTR is linked to cystic fibrosis.