Untreated, no known HER2-positive status, PD-L1 expression ≥ 5%, unresectable advanced or metastatic G/GEJ adenocarcinoma. 73.1% male, 43.2% with age ≥ 65 years, 24.6% ECOG 0, all patients were from China. Here, CD274 is linked to gastroesophageal junction adenocarcinoma.