CD274 and cancer: ICB, such as anti-PD-1 and anti-PD-L1 mAb, would optimize the anti-tumor activities of cancer-vaccine-induced T cells by inhibiting the interaction of PD-1 on these activated tumor-specific T cells with PD-L1/-L2 on the target cell surface, overcoming T-cell exhaustion and resulting in malignant cell eradication.