However, although IL-6 has no significant distinct effect on the tumor cell invasion, once the IL-6 was knocked out, the negative pro-invasive effect of the single treatment could be eliminated, which suggests that sorafenib is suitable for tumor cells with low IL-6 expression because of its ability to counteract the pro-invasive side effects by the anti-tumor therapy by the down-regulation of p-MEK and p-ERK when IL-6 was knocked-out. This evidence concerns the gene IL6 and neoplasm.