This analysis of RTK expression in dysplastic lesions of the gastroesophageal junction confirms that (1) HER family proteins are upregulated in Barrett’s esophagus with dysplasia; (2) the frequency of HER family overexpression is positively correlated with the degree of dysplasia; and (3) HER protein upregulation, particularly HER2 and HER3, in dysplastic lesions is associated with an increased incidence of associated invasive cancer. This evidence concerns the gene ERBB2 and esophageal adenocarcinoma.