CD274 and cancer: In this review, we focus on the following four strategies: 1) Cancer vaccines, especially personalized vaccines based on neoantigens, can activate specific immune responses; 2) Immune checkpoint inhibitors (ICIs) to reverse T cell exhaustion (e.g., anti-PD-1/PD-L1 antibodies); 3) Adoptive immune cell therapies, particularly chimeric antigen receptor T-cell (CAR-T) therapy, have shown encouraging results in preclinical trials; 4) Oncolytic viruses, which have dual roles of directly lysing tumor cells and stimulating immune responses.