TNF and pheochromocytoma: Tyrosine hydroxylase is induced by EGFR as shown in clonal pheochromocytoma cell line [54]; its overexpression leads to decreased interferon (IFN)-γ and tumor necrosis factor (TNF) levels as shown for lymphocytes [23], which could be a marker for poor prognosis [55], and activates the xc(-) system [56].