Several immune checkpoint inhibitors (ICIs) have received approval as first-line immunotherapy for non-HER2-positive/HER2-negative advanced or metastatic GC or gastroesophageal junction cancer (GEJC) in several phase 3 trials, including CheckMate-649, KEYNOTE-859, ORIENT-16, RATIONALE-305, etc. [3,4,5,6,7]. This evidence concerns the gene ERBB2 and gastric cancer.