The programmed cell death 1 (PD-1) is an important immunosuppressive molecule, which could initiate the programmed death of T cells via combination of programmed death ligand 1, and then enable tumor cells to obtain immune escape.30,31 Surprisingly, the level of PD-1 was significantly downregulated in γδ T cells after combination treatment (Fig. 5b). This evidence concerns the gene PDCD1 and neoplasm.