ERBB2 and gastric cancer: So far, the licensed targeted therapies for gastric cancer include trastuzumab (anti-human epidermal growth factor receptor 2, anti-HER2 antibody), ramucirumab (anti-vascular endothelial growth factor 2 receptor antibody), and nivolumab or pembrolizumab (anti-programmed death 1, anti-PD1 antibody) [3].