In the ad-hoc analysis of the phase III Trastuzumab for Gastric Cancer (ToGA) study, GC or GJC patients with HER2 IHC 2+/in situ hybridization positivity, or IHC 3+, achieved the greatest OS benefit (16.0 vs. 11.8 months) [8]. This evidence concerns the gene ERBB2 and gastric cancer.