CFTR and diabetes mellitus: Although the involvement of β-cell CFTR in the appearance of the insidious intermittent hyperglycemia in CFRD remains to be determined, the concept is relevant when considering that the existing relationship between CFRD and exocrine pancreatic insufficiency [48] does not explain the fact that CFRD also occurs in patients without pancreatic insufficiency and that the latter is not a necessary condition to develop diabetes [49].