Respectively, the pooled ratios of OS-HRs and PFS-HRs reported in patients with positive versus negative PD-L1 expression were 1.26 (95% CI = 0.91 to 1.73; Figure 4C) and 1.08 (95% CI = 0.77 to 1.52; Figure 4D), and this heterogeneity indicated that ES-SCLC patients with negative PD-L1 expression may be more suitable candidates for chemoimmunotherapy. The gene discussed is CD274; the disease is small cell lung carcinoma.