In addition to secreting the catecholes dopamine, epinephrine and norepinephrine, numerous other hormones have been isolated from pheochromocytomas including adrenocorticotropin, vasoactive intestinal peptide, neuropeptide Y, IL-6, calcitonin, and chromogranin A. Here, NPY is linked to hereditary pheochromocytoma-paraganglioma.