Hepatic ablation of PTEN as a tumor suppressor and the PI3K/AKT signal controller, which resulted in fatty liver and hepatocellular carcinoma [47], also upregulated FGF21 expression at about 25 times in the PTENf/fAlbCre livers than those of PTENf/f controls (Figure 2B). Here, FGF21 is linked to hepatocellular carcinoma.