The addition of the glucagon-like peptide 1 (GLP-1) receptor agonists or of a sodium–glucose cotransporter 2 (SGLT2) inhibitor to insulin therapy was shown to trigger small reductions in HbA1c compared with insulin alone in people with type 1 diabetes and also reduced body weight (27–29). The gene discussed is GLP1R; the disease is type 1 diabetes mellitus.