After reviewing the abstracts and full texts based on the set inclusion and exclusion criteria, 5 studies evaluating HER3 overexpression and GC [21–25], 4 detailing HER2-HER3 co-expression [14–16, 25], 3 describing mTOR [26–28], 7 researching p-mTOR [28–34], 2 exploring Akt [34, 35], and 12 that researched p-Akt overexpression in GC [33, 34, 36–45] were finally selected (Additional file 2: Figure S1). The gene discussed is ERBB2; the disease is gastric cancer.