In summary, the in vivo knockdown of Ngp in CD4 and CD8 T cells controlled classical ICI molecules, including PD-1, 4-1BBL, and CD160, reduced Tregs and increased CD25 expression on the transduced T cells, suggesting an enhanced T cell activation and reduced immunosuppression in HCC-bearing mice. This evidence concerns the gene PDCD1 and hepatocellular carcinoma.