ERBB2 and esophageal adenocarcinoma: Several studies have reported the dual overexpression of HER-1 and HER-2 in EC with extremely high rates in esophageal adenocarcinoma when compared to that of squamous cell carcinomas of the esophagus [39,40,41,42]; thus, there is a potential clinical benefit in co-targeting HER-1 and HER-2 in EC [32,43].