To further clarify the anti-tumor mechanism, qPCR showed TGF-β1 siRNA-αPDL1-NPs led to a significant decrease of TGF-β1 expression levels (Figure 9), which increased the number of CD8+ T cells in the tumor center and converted the immune-excluded phenotype to the inflamed phenotype (Figure 5), causing robust antitumor immunity and reducing tumor burden. This evidence concerns the gene CD8A and neoplasm.