ERBB2 and gastric cancer: While there have been investigations on the clinical significance of Her2 expression in patients with gastric cancer, they mostly investigated Her2 alone, and a large proportion of the studies were on advanced unresectable gastric cancer; furthermore, the associations of Her2 expression with clinicopathologic factors (especially tumor pTNM stage, pT stage, pN stage, and differentiation) and prognosis remain largely controversial, and the quality of statistics in previous studies varied [13, 28].