CD274 and cancer: As for PFS/DFS, the pooled HR of 23 eligible studies that included 3821 cancer patients was 1.72 (95% CI = 1.26–2.33, P = .001), which suggested that PD-L1 overexpression was a poor prognosis indicator for multiple solid cancers, and significant heterogeneity was found across the studies (I2 = 81%, P <.000), as shown in Fig. 3 and Table 2.