Surprisingly, intake of 67 % High BCAA ameliorates NAFLD by inhibiting tryptophan-ILA-AHR and activating MAPK9 ubiquitination, inhibiting DNL and steatosis, increasing hepatic insulin sensitivity, promoting ketogenesis and fatty acid oxidation via activating PPAR-RXR and pexophagy. The gene discussed is TNFRSF9; the disease is steatosis.