CD274 and neoplasm: In comparison with Lin et al.’s study, our investigation demonstrated that anti-PD-L1 Ab could enhance antigen-specific anti-tumor effects by modulating immune cells in immune-competent mice, compared to different anti-tumor mechanisms through neutralizing E6 protein by Lm-LLO-E6 vaccine to further inhibit PD-L1 expression, and consequently could suppress tumor growth in immunocompromised mice [22].