The biological effects of GIP on β-cells in the pancreas are mainly regulated by the high-affinity receptor for GIP (GIPR) [7,8] and a novel dual GIP and glucagon-like peptide-1 (GLP-1) receptor agonist, tirzepatide, has been developed for the treatment of patients with type 2 diabetes [9,10,11]. The gene discussed is GIP; the disease is type 2 diabetes mellitus.