CFTR and cystic fibrosis: Moreover, while polarized CFBE and Caco2 monolayers do not fully recapitulate the properties of differentiated epithelia in vivo, these models have been extensively used to study the mechanisms of CF disease and, in the case of CFBE cells, for the development and characterization of several CFTR modulator drugs13–15,52,53, where they have been shown to respond similarly to primary airway cells20,52,53.