A phase I study of fisogatinib (BLU-554) validated that aberrant FGF19/FGFR4 signaling is a targetable oncogenic driver in HCC; fisogatinib was well-tolerated and most adverse events were manageable grade 1/2 gastrointestinal event – primarily diarrhea, nausea, and vomiting (Kim et al., 2019). Here, FGFR4 is linked to hepatocellular carcinoma.