FGFR4 and hepatocellular carcinoma: As discussed in the FGF19 section, the abnormality of FGF19-FGFR4-KLB is involved in HCC cell proliferation, survival, EMT, migration, and invasion (Ho et al., 2009; Yang et al., 2012b; French et al., 2012; Lin and Desnoyers, 2012; Liu et al., 2015b; Gu et al., 2015; Sheu et al., 2015; Lin et al., 2019b).