ERBB2 and esophageal cancer: In this study, RT-PCR was applied to detect the expression level of gene mRNA of epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), and human epidermal growth factor receptor 2 (HER-2), which are related with esophageal cancer proliferation, invasion, angiogenesis, and tumor metastasis; the relationship between the expression and the clinicopathological factors is discussed in the following text.