There are increasing numbers of effective drugs to improve obesity-linked metabolic dysfunction; GLP-1R-GIPR co-agonism is effective in the management of obesity and type 2 diabetes<sup>1,2</sup>, and lanifibranor-a nuclear-acting small-molecule triple agonist of PPARα, PPARγ and PPARδ-is in clinical phase 3 trials for the treatment of metabolic dysfunction-associated steatohepatitis<sup>3</sup>. The gene discussed is GIPR; the disease is obesity due to melanocortin 4 receptor deficiency.