Combination regimens, including a fluoropyrimidine and a platinum agent (plus trastuzumab as an anti HER2 monoclonal antibody for HER2-positive cases) at first-line and paclitaxel with or without ramucirumab at second-line, are standard treatment for advanced unresectable or recurrent gastric cancer (AGC). This evidence concerns the gene ERBB2 and gastric cancer.