To elucidate the role of KAL in NAFLD, we generated KAL gene knockout (Serpina4−/−) rats and fed them with a HFruD for 16 weeks to induce an HTG non-obese NAFLD model (Fig. 3a), and found that the expression of KAL in the liver was higher in HFruD rats; Serpina4−/− rats showed a significant improvement in hepatic steatosis in HFruD rats (Fig. 3b-c). Here, SERPINA4 is linked to fatty liver disease.