This rate was higher than that demonstrated in the ToGA trial (16.6%)—when taking into account the applied definition of higher HER2 overexpression (IHC 2+/FISH-positive or IHC 3+), or lower (22.1%)—when the definition of HER2 positivity included all FISH-positive cases in addition to IHC 3+ samples, and finally, it was quite comparable (20.6%)—when only cancers of the stomach rather than both stomach tumors and those of the gastroesophageal junction (GEJ) were considered [49, 50]. The gene discussed is ERBB2; the disease is gastric cancer.