ERBB2 and gastric cancer: Although the Food and Drug Administration (FDA) has approved different therapeutic antibodies, such as trastuzumab, ramucirumab and pembrolizumab, as first- and second-line treatments for GC [2, 3], their efficacies are poor on gastric cancer since only a small portion of patients are HER2 (~ 20%), VEGF and PD-1/PD-L1 positive [4, 5].