FGFR4 and hepatocellular carcinoma: FGF19-FGFR4 signaling activates several signaling pathways including extracellular regulated protein kinase (ERK), Jun N-terminal kinase (JNK), phosphoinositide 3-kinase (PI3K), protein kinase C (PKC), mammalian target of rapamycin (mTOR), and signal transducer and activator of transcription 3 (STAT3) to promote HCC carcinogenesis, progression and metastasis29.