CD274 and esophageal squamous cell carcinoma: Pembrolizumab–chemotherapy was superior to placebo–chemotherapy for overall survival (OS) in the total population (hazard ratio [HR], 0.73; P < 0.0001) and in patients with ESCC (HR, 0.72; P = 0.0006), PD-L1 CPS ≥ 10 (HR, 0.62; P < 0.0001), and ESCC PD-L1 CPS ≥ 10 (HR, 0.57; P < 0.0001) [9].