In gastric cancer, HER-2 overexpression was observed to be associated with aggressiveness and poor outcomes.7,13 The study on trastuzumab for gastric cancer (ToGA trial) demonstrated that the addition of trastuzumab to chemotherapy was beneficial for advanced HER-2 positive gastric cancer.14 Trastuzumab has been approved for the treatment of patients with HER-2 positive metastatic adenocarcinoma of the stomach or gastroesophageal junction.15 Here, ERBB2 is linked to gastric cancer.