Tirzepatide is a once weekly, single molecule dual glucose‐dependent insulinotropic polypeptide (GIP) and glucagon‐like peptide‐1 (GLP‐1) receptor agonist approved in adults for the treatment of T2D, obesity, and (in the US) moderate to severe obstructive sleep apnea in patients with obesity. The gene discussed is GIP; the disease is obesity due to melanocortin 4 receptor deficiency.