PTPN6 and breast cancer: Low levels of PTPN6, also known as Src homology region 2 domain-containing phosphatase-1 (SHP-1), are predictor of improved disease-free survival, and could be a useful biomarkers to predict clinical outcome of breast cancer patients.(28) Interestingly, PTPN6 can be self-regulated and is essential for the inhibitory function of NK cells.(29) The cytokine IL-12β seems to be critical in inflammation and adaptive immune responses.