GLP‐1 is primarily known as an insulinotropic hormone, which together with glucose‐dependent insulinotropic polypeptide (GIP), is responsible for the incretin effect, ie, the markedly increased insulin secretion after oral as opposed to i.v.‐administered glucose.3 The effect of GLP‐1 on insulin secretion is being exploited in the treatment of type 2 diabetes mellitus, where GLP‐1 receptor agonists (GLP‐1RAs) are widely used. The gene discussed is GLP1R; the disease is diabetes mellitus.