To determine the potential therapeutic mechanisms underlying the efficacy of PLGA (PD-L1 siRNA+PD-1 siRNA)-NPs in tumor tissues, we examined the tumors for PD-L1 (anti-PD-L1) and PD-1 (anti-PD-1) expression, infiltration of CD8+ T cells (anti-CD8), cell proliferation (anti-Ki67), and apoptosis (TUNEL assay) (figure 5D). This evidence concerns the gene PDCD1 and neoplasm.