ERBB2 and gastric cancer: HER2 overexpression is detectable in 13–23% of all GCs [3], and the addition of the monoclonal antibody against erbB-2 (Her-2/neu), trastuzumab to chemotherapy resulted in a significant advantage of patient survival for HER2 overexpressing GC patients (median OS: 13.8 vs. 11.1 months, hazard radio HR: 0.74; 95% confidence interval: 0.60–0.91, p = 0.0046) [4].