CD274 and gastric cancer: Based on the CheckMate 649 study, on April 16, 2021, the Food and Drug Administration (FDA) approved nivolumab in combination with fluorouracil and platinum agents as the new first-line treatment strategy for patients with advanced or metastatic GC/GEJC/esophageal adenocarcinoma, regardless of PD-L1 expression status, followed by NCCN Guidelines (2021 edition) recommended.