In Japan, the current standard of care for unresectable advanced, recurrent, or metastatic GC in the first-line setting is systemic chemotherapy with a fluoropyrimidine plus platinum-based agent with or without nivolumab for human epidermal growth factor receptor 2 (HER2)–negative tumors or a trastuzumab-containing regimen for HER2-positive tumors [3]. Here, ERBB2 is linked to gastric cancer.