CFTR and cystic fibrosis-related diabetes: It is evident that exocrine fibrotic damage alone cannot completely explain the development of CFRD [43,44], and several additional factors may contribute to either beta-cell mass reduction or beta-cell dysfunction: (a) the CFTR defect; (b) genetic factors related and not related to T2D; (c) inflammation; (d) changes in the incretin axis [38].