GCG and type 2 diabetes mellitus: For T2D (Fig. 1d and e), they comprised (monogenic) GLP-1-related pathways stimulating secretion of insulin-containing granules by β-cells, potassium channels regulating glucose-induced action potential firing, and the group of pathways underlying stress-induced β-cell death, including unfolded protein response, cell cycle/DNA repair regulated by p53, and mitochondrial apoptosis pathways.