Compared to treatment with inCT†CMVp480–516 alone, the combined treatment did not provide any additional antitumor effects (Fig. 4E,F) nor did it increase the number and cytotoxicity of tumor-infiltrating CMVp-CTLs (Fig. 4G), even though PD1 and its ligand PD-L1 were expressed on the surface of CMV-CTLs (Fig. S5C) and MDA-MB-231 cells (Fig. S2), respectively. Here, PDCD1 is linked to neoplasm.