In this trial, patients with untreated HER2-negative and PD-L1-positive (CPS ≥ 1%) advanced GC were randomly allocated to three arms with two comparisons: pembrolizumab monotherapy (non-inferiority) vs. FP/XP plus placebo and FP/XP plus pembrolizumab (superiority) vs. FP/XP plus placebo. The gene discussed is ERBB2; the disease is gastric cancer.