Increased plasma levels of glucagon‐like peptide 1 (GLP‐1) and FGF‐21 were found to contribute to the improved glycemic control in Gcgr−/− mice and to work in a complementary way to prevent postprandial hyperglycemia in mice lacking insulin and glucagon action (Omar et al., 2014). The gene discussed is GCG; the disease is Hyperglycemia.