Interestingly, the sorafenib pERK inhibition effect in SMMC-7721 cells with lower initial levels of pERK was significantly weaker when compared to the other three HCC cell lines with relatively higher basal pERK levels (P < 0.0001, n = 6; Figure 2B), and it should be noted that this difference was mainly at 10 μM sorafenib. This evidence concerns the gene EIF2AK3 and hepatocellular carcinoma.