ERBB2 and gastric cancer: HER2-targeted therapy with trastuzumab plus chemotherapy in advanced HER2-positive gastric cancer has improved median overall survival (OS) from 11.1 to 13.8 months (hazard ratio 0.74, 95% CI 0.60–0.91), reaching 16.0 vs. 11.8 months when in the most strongly HER2-positive subgroup (immunohistochemistry (IHC) 3+ or IHC 2+ with fluorescence in situ hybridization (FISH) positivity) compared to conventional chemotherapy regimens [6].