STAT3 and hepatocellular carcinoma: Because SHP-1 tyrosine phosphatase activity could negatively regulate HCC EMT by mediating the inactivation of STAT3 [14], we then evaluated whether SHP-1 tyrosine phosphatase activity is involved in the effects of regorafenib on reducing TGF-β1-induced p-STAT3Tyr705, which is required for EMT.