Paracrine signals from ductal epithelium have been proposed to play a role inislet physiology.68 Ductal cells produce TGF-α and regulate islet differentiation.69 TGF-α is overtly upregulated in ductal cells in the context of chronic pancreatitis,70 showing that intra-pancreatic crosstalk between exocrine and endocrinetissue could be important in the development of CFRD. The gene discussed is TGFA; the disease is cystic fibrosis-related diabetes.