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. The gene discussed is ERBB3; the disease is esophageal adenocarcinoma.