The one-stage IPD-pooled analysis, based on the PD-L1 CPS scoring system, confirmed that non-HER2-positive/HER2-negative advanced or metastatic GC or GEJC with a negative PD-L1 expression (CPS < 1) and a low expression (CPS < 5) had no significant OS and PFS benefits from first-line immunotherapy. Here, ERBB2 is linked to gastric cancer.