PTPN11 and cancer: Soluble factors in the microenvironment and immunosuppressive cells are speculated to attenuate the IFN-γ response of NK, NKT, CTL, and γδT cells; it is hypothesized that oncogenic signals, such as SOCSs and SHP2, in malignancies also cause cellular hyporesponsiveness, such as immune evasion, in response to IFN-γ anticancer activities, including cancer cell growth inhibition, cytotoxicity, and MHC class I expression.