PTPN6 and cancer: Recently, it has been demonstrated that sorafenib and its derivatives directly enhance the activity of Src homology region 2 (SH2) domain-containing phosphatase 1 (SHP-1) and which specifically decreases the phosphorylated form of STAT3 at Tyr705 (p-STAT3Tyr705) and eventually leads to cancer apoptosis and suppressed tumorigenicity [6, 7].