In the ToGA study, trastuzumab combined with a fluoropyrimidine [capecitabine or 5-fluorouracil (5-FU)] plus cisplatin was found to be more effective and tolerable in HER2-positive advanced gastric cancer and gastroesophageal junction cancer (GEJC) compared with placebo plus chemotherapy [5, 10]. Here, ERBB2 is linked to gastric cancer.