RET and neoplastic syndrome: Paragangliomas and pheochromocytomas can occur sporadically or in the context of several inherited tumor syndromes, including multiple endocrine neoplasia type 2 (MEN2, with RET germline mutations), von Hippel-Lindau (VHL) disease (caused by germline mutations in the VHL gene), neurofibromatosis type 1 (NF1, with NF1 gene germline mutations) and pheochromocytoma-paraganglioma syndrome.