Because of the multiple metabolic functions of FGF15/19 and PPARα in the regulation of BA homeostasis and glucose and lipid metabolism, single PPARα activation or FGF15/19 has been studied in several preclinical and clinical MASLD/MASH models, with the outcome not optimistic for MASH resolution. The gene discussed is PPARA; the disease is metabolic dysfunction-associated steatohepatitis.