CFTR and cystic fibrosis: These results are in accordance with the data found in CFTR−/− rats generated by Tuggle et al, except for ileal tissue which showed epithelial cell sloughing and crypts dilated with mucus in their model.8 Moreover, Birket et al showed that in rat airways, CF‐related abnormalities such as SMG hypertrophy and increased mucus viscosity appeared after 6 months.10 This suggests that CF‐related disease appears with age and that our rat models were probably too young to exhibit histological alterations.