Overactivation of the PI3K/AKT/mTOR pathway, characterized by the production of phospho-AKT (p-AKT), phospho-mTOR (p-mTOR), phospho-S6 (p-S6) and vascular endothelial growth factor (VEGF), occurs in many tumors such as renal cancer, adrenal carcinoma and pheochromocytoma, but it has not been examined in PA [6], [7]. Here, MTOR is linked to pheochromocytoma.