Programmed death-ligand 1 (PD-L1) is the key elementof the PD-1/PD-L1 axis that induces apoptosis of T cells, inhibitstheir proliferation and provides immune escape of cancer cells.140,141 Down-regulation of PD-L1 is a potential strategy in the eliminationof cancer cells by enhancing the cytotoxicity of T cells against tumorcells.142 The combination of DOX and siRNA-PD-L1is beneficial in anticancer therapy. This evidence concerns the gene CD274 and cancer.