The “Src homology region 2-containing protein tyrosine phosphatase 2” (SHP2) is a ubiquitous tyrosine phosphatase, activating the signal transduction (including the JAK/STAT pathway) of various growth factors and cytokines: it may act as an oncoprotein (promoting proliferation and survival), but also as a tumor suppressor in some cancers [142,165]. Here, PTPN11 is linked to cancer.