The ToGA trial added trastuzumab to standard chemotherapy, which led to a significant survival benefit for patients with HER2-positive advanced G/GEJ adenocarcinoma (median OS, mOS 13.8 vs. 11.1 months; P = 0.046); consequently, trastuzumab in combination with chemotherapy is now the current first-line standard of care for patients with advanced metastatic HER2-positive GC [10]. The gene discussed is ERBB2; the disease is gastric cancer.