HER-2-specific Ptpn2fl/fl versus Lck-Cre;Ptpn2fl/fl versus Lck-Cre;Ptpn2fl/fl;Lck+/- CAR-T cells were incubated with HER-2 expressing 24JK sarcoma cells (24JK-HER-2) or HER-2 negative 24JK sarcoma cells and CD44, CD25, PD-1 and LAG-3 MFIs on CD8+ CAR-T cells were determined by flow cytometry. 