It is worth noting that all Cholangiocarcinoma (2.78%), Pheochromocytoma & Paraganglioma (2.25%), Mesothelioma (1.15%) and Testicular Germ Cell (0.67%) Tumors have copy number deletion of MTHFR (Fig. 3A). The gene discussed is MTHFR; the disease is pheochromocytoma.