Our patient had slightly increased morning serum fasting cortisol (28.5 μg/dL, normal 5–25) and urinary cortisol (435 μg/24 hours, normal 70–320), as previously observed in a patient affected by IL-6-producing pheochromocytoma [9]. This evidence concerns the gene IL6 and hereditary pheochromocytoma-paraganglioma.