The immunostaining with a glucagon antibody revealed intact islets with alpha cells located in the periphery of islets in WT and Cdnf−/− mice, but infiltrated islets with alpha cells revealed disturbed islet morphology in the Cdnf+/−::Manf−/− and Cdnf−/−::Manf−/− mice (Fig. 2f).Thus, the severity of beta cell loss and diabetes in Manf−/− mice was not affected by CDNF deficiency. Here, GCG is linked to diabetes mellitus.