FGFR4-IN-8 (Compound 7v) is an ATP-competitive inhibitor that covalently and highly selectively targets both the wild-type and gatekeeper mutant forms of FGFR4. It shows excellent inhibitory potency with IC50s of 0.5 nM for FGFR4, 0.25 nM for FGFR4 V550L, 1.6 nM for FGFR4 V550M, and 931 nM for FGFR4 C552S. Additionally, FGFR4-IN-8 has a potent antiproliferative effect on Hep3B hepatocellular carcinoma cells, with an IC50 of 29 nM, and demonstrates moderate antitumor efficacy in vivo in a Huh-7 xenograft model in nude mice [1].