Cytotoxic CD8+ T cells were increased in both peripheral blood (0.66 x 105 to 3.34 x 105; P≤0.0001) and tumor (0.53 x 103 to 1.83 x 103; P≤0.0001) in mice treated with NT-I7 when compared to control. Similarly, NT-I7 in combination with RT increased the CD8+ T cells in peripheral blood (0.658 x 105 to 1.839 x 105 P≤0.0001) when compared to RT alone....NT-I7 enhances cytotoxic CD8+ T lymphocytes systemically and in the tumor microenvironment, and improves survival.