GCG and cystic fibrosis-related diabetes: It has also been reported that CFTR is localized in rat glucagon-secreting α cells (Boom et al., 2007; Edlund et al., 2017) and disrupted glucagon level is also observed in CFRD patients (Hinds et al., 1991; Lanng et al., 1993; Edlund et al., 2017), suggesting possible involvement of CFTR in the regulation of glucagon production; however, its exact role in pancreatic islet α cells remains unknown.