Participants with unresectable tumors, PD-L1 CPS ≥ 5, non-HER2-positive GC, GEJ, or esophageal adenocarcinoma were classified into 3 groups and received nivolumab plus chemotherapy (oxaliplatin plus capecitabine or fluorouracil, leucovorin), nivolumab plus ipilimumab, or chemotherapy alone, respectively. This evidence concerns the gene ERBB2 and gastric cancer.