ERBB2 and gastric cancer: The study inclusion criteria included: (1) studies published in the English language, (2) patients diagnosed with HER2-positive GC/GEJC, (3) studies reporting completed phase II or III trials, and (iv) studies reporting the efficacy and/or safety of the HER2-targeting TKIs lapatinib, afatinib, dacomitinib, and neratinib.