H&E staining and Oil Red O staining analysis revealed that liver tissues of KK-Ay mice had obvious NAFLD characteristics with extensive fat vacuoles, liver cells balloon-like transformation, and interstitial inflammatory cell infiltration (Fig. 6A–C), which were consistent with the high serum TG, TC, LDL-C, ALT, AST, and TNF-α. The gene discussed is TNF; the disease is metabolic dysfunction-associated steatotic liver disease.