Tumor evasion from the host immune system is a substantial strategy for tumor development and survival. The expression of many immune checkpoint proteins in cancer cells is a mechanism by which tumor cells escape from the immune system.Among the well-known immune checkpoints that can tremendously affect tumor development and cancer therapy are the programmed death-ligand-1/programmed death-1 (PD-L1/PD-1). To tackle this phenomenon and improve the therapeutic strategies in cancer treatment, the blockade of the PD-L1/PD-1 pathway is introduced as a target, but the therapeutic advantage of PD L1/PD-1 blockade has not