Moreover, recent studies indicate that up to 25% of pheochromocytoma patients have a genetic background (NF1, VHL, SDHD, SDHB or RET gene mutations) and thus both the patients and their closest blood relatives require wide multidisciplinary diagnostics as well as long-term follow-up [18,19]. The gene discussed is RET; the disease is hereditary pheochromocytoma-paraganglioma.