Case #1 (EPAS1 variant c.581A>G, p.His194Arg) together with VHL mutation c.350G>C, p.Trp117Ser) was a man who had resection of a right phaeochromocytoma aged 30 years, and who also had bilateral renal masses, a pancreatic neuroendocrine tumor and recurrent hemangioblastomas consistent with diagnosis of VHL syndrome; his most recent hematocrit values have ranged between 0.45 and 0.52 (normal range 0.39–0.54). The gene discussed is VHL; the disease is von Hippel-Lindau disease.