Quadruple immunofluorescence analysis of chromogranin-A, insulin, glucagon, and MDA5 as well as quadruple immunofluorescence analysis of somatostatin, insulin, glucagon, and MDA5 in the pancreatic tissue of T1D donors (Supplementary Figures 3A, B) further confirmed that MDA5-positive cells were endocrine but not somatostatin-positive, thus exclusively α- or β-cells. Here, GCG is linked to type 1 diabetes mellitus.