However, the clinical effectiveness of PD-1/PD-L1 pathway blockade as a monotherapy is observed in only approximately 10% of gastric cancer (GC) patients.3–5 The addition of anti-PD-1/PD-L1 antibodies to chemotherapy has demonstrated superior efficacy compared to chemotherapy alone in previously untreated patients with advanced gastric cancer (GC). This evidence concerns the gene PDCD1 and gastric cancer.