The study data show that CUDC-907 (fimepinostat), a novel dual acting inhibitor of phosphoinositide 3-kinase (PI3K) and histone deacetylase (HDAC), has potent inhibitory effects on HCC cell lines and primary HCC cells in vitro, Animal studies have shown that CUDC-907 can also suppress HCC cells in vivo. This evidence concerns the gene HDAC9 and hepatocellular carcinoma.