On the Mann-Whitney U-test, FGF-21 levels were significantly higher in the high-grade liver steatosis group than in the low-grade liver steatosis group, simple obese children, and healthy controls (median [IQR], 183.17 [113.03–301.14] pg/mL vs. 86.58 [62.76–183.02] pg/mL vs. 79.76 [30.91–146.76] pg/mL vs. 53.45 [29.78–87.21] pg/mL, P < 0.001, respectively) (Figure 1A). Here, FGF21 is linked to fatty liver disease.