PDCD1 and esophageal cancer: Compared to placebo–chemotherapy, observed OS, PFS, and ORR improvements with pembrolizumab–chemotherapy were consistent with those of the global KEYNOTE-590 population [1, 5] and were comparable to results from other randomized studies for PD-1 inhibitors plus chemotherapy as first-line treatment of patients with advanced esophageal cancer from global and Japanese populations [12–17].