IGHE and cystic fibrosis: Moreover, Cftrfl/fl/Villincre/− animals that do not show intestinal mast cell increase or increased IgE are still affected by increased lethality due to intestinal obstruction of lesser extent than for the CftrΔF508/ΔF508 or Cftr−/− animals (Supplemental Fig. 1 and Hodges et al. 47), suggesting a role for epithelial cells and additionally for immune cells of the intestine in the development of CF intestinal disease.