Hegel and colleagues reported that BLU9931, an FGFR4-specific inhibitor, inhibits the proliferation of cell lines in which the FGF19/FGFR4 signaling pathway is activated, and exhibits antitumor activity as observed in a murine xenograft model carrying the same HCC cell line [17]. The gene discussed is FGFR4; the disease is hepatocellular carcinoma.