EGFR and neuroendocrine neoplasm: The purification of betacellulin, a pan-ErbB EGF family ligand, from the conditioned media of RT2-derived cancer cells23 and the fact that a majority of human neuroendocrine tumors express phosphorylated Egfr24 suggested a possible involvement of ErbB signaling in multistage pancreatic neuroendocrine carcinogenesis.