PDCD1 and breast cancer: As we have reported previously11,14, the deletion of either PTP1B or PTPN2 in T cells was sufficient to repress the growth of AT3-OVA mammary tumors (Fig. 5a, b) and promote the recruitment of TILs, including CD4+ and CD8+ effector/memory T cells and activated CD8+ T cells with enhanced cytotoxic potential (Fig. 5c), as reflected by the proportion of cells staining for the cell surface markers PD-1 and Tim-3 and those staining intracellularly for IFNγ, TNF and Granzyme B (Fig. 5d).