Elevation of hepatic FGF21 expression during genetic hepatocarcinogenesis and perturbation. Hepatic FGF21 mRNA levels were analyzed by quantitative PCR in the mouse liver tissues under different perturbation conditions at an age of one year. mRNA levels are expressed as fold changes relative to that in the wildtype or control mouse livers, which is assigned as an arbitrary unit 1. A : Increase of FGF21 mRNA levels in mouse livers with haploinsufficiency for tumor suppressors LKB1 and p53. Changes in expression of FGFR4 and KLB were also measured in the corresponding tissues. *p < 0.05 (n = 6). WT: wildtype. B : Increase of FGF21 mRNA levels in mouse livers with conditional ablation of tumor suppressors SAV1, compound MST1/MST2 or PTEN. f/f: floxed alleles for SAV1, MST1/MST2 or PTEN genes. −/−: ALB-Cre mediated hepatic deletion of SAV1, MST1/MST2 or PTEN. *p < 0.05 (n = 3-5 for each data point). C : Changes in the corresponding serum FGF21 protein levels in mice used in (B) were determined as in Figure 1B inset. D : Changes of hepatic FGF21 mRNA levels after whole-body knockout of KLB or FGFR4. *p < 0.05 (n = 6 for each data point). KO: whole-body knockout.