The pooled results of a meta-analysis showed that PD-L1 overexpression could predict poor OS (HR 1.45, 95% CI: 1.11-1.90, P<0.01), metastasis-free survival (HR1.58, 95% CI: 1.14-2.19, P<0.01) and event-free survival (HR 2.82, 95% CI: 1.69-4.71, P<0.01) in OSs, and was also significantly correlated with a higher rate of tumor metastasis (OR 2.95, 95% CI: 1.32-6.60, P< 0.01) [34]. This evidence concerns the gene CD274 and neoplasm.