The estimated 24-month PFS rate in the pembrolizumab–chemotherapy group versus placebo–chemotherapy group was 19.0% versus 2.3% in all randomly assigned patients, 21.4% versus 2.7% in patients with ESCC, and 21.3% versus 0% in patients with PD-L1 CPS ≥ 10. Here, CD274 is linked to esophageal squamous cell carcinoma.