ERBB2 and esophageal squamous cell carcinoma: Several genetic alterations associated with development and progression of ESCC have been described, including TP53, cyclin D1, E-cadherin, Bcl-2, TNF-alpha, NF-kappaB, TGF-beta, MMP-7, COX-2, EGFR, HER2/neu, and HIF-1 alpha [5].