Therefore, our in vitro findings of sorafenib- and SOR+CLX-mediated down-regulation of FGF19 mRNA in Huh7 cells indirectly suggest that FGF19 could be potentially used in HCC patients as a serum biomarker for monitoring the effects of sorafenib, and possibly other treatments. The gene discussed is FGF19; the disease is hepatocellular carcinoma.