Incretins, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) act on pancreatic β cells to stimulate glucose-responsive insulin secretion, but also have tissue-protective effects beyond lowering blood glucose levels [3], such as cardiovascular protection [4], anti-hepatic steatosis [5] and anti-Alzheimer’s disease [6]. Here, GCG is linked to early-onset autosomal dominant Alzheimer disease.