In this study, the investigators are examining the role of the immune system in pheochromocytoma and paraganglioma. The investigators aim to examine the differences in the immune system between people who have these tumors with and without a hereditary predisposition. The investigators also want to see how the immune system changes during the development of the tumor in people with a hereditary predisposition. Finally, the investigators will compare the data with a control group of people without these tumors. Ultimately, the investigators hope that the results will contribute to the discovery of new immune system-targeted medications for pheochromocytoma and paraganglioma.