For example, there is a trial investigating fisogatinib, an FGFR4 inhibitor, in patients with FGF19 IHC + HCC, as FGF19 is the endogenous ligand for FGFR4, which is the most common of the fibroblast growth factor receptors in the liver [71,82,83]. Here, FGFR4 is linked to hepatocellular carcinoma.