CD274 and neoplasm: The pooled results did not reach a significant difference in OS, both among tumor PD‐L1‐positive patients (HR = 0.40, 95% CI: 0.08–1.94) and tumor PD‐L1‐negative patients (HR = 0.47, 95% CI: 0.17–1.31); a significant heterogeneity was observed (Q test, p < 0.01) (Figure S4A).