The combination of trastuzumab with chemotherapy in HER2-positive advanced gastric cancer patients as first-line therapy and the addition of ramucirumab to taxane in non-selective advanced gastric cancer patients as second-line therapy exhibited modest survival benefits [10, 11], whereas other targeted agents, including bevacizumab, everolimus, and cetuximab, did not show overall survival gain without the use of biomarker enrichment strategies [12–14]. The gene discussed is ERBB2; the disease is gastric cancer.