However, one important reason must be considered for the variation in the overexpression, which is what Chung et al.[25] found in their screening program for the ToGA: HER-2 positivity rates differed by tumor locations and types, for example, rates were higher in the gastroesophageal junction than in stomach cancer and higher in intestinal than in diffuse or mixed cancer. The gene discussed is ERBB2; the disease is gastric neoplasm.