MEN1 and von Hippel-Lindau disease: Key syndromes include multiple endocrine neoplasia type 1 (MEN1), von Hippel–Lindau disease (VHL), neurofibromatosis type 1 (NF1), and tuberous sclerosis complex (TSC), which are characterized by germline mutations in the tumor-suppressor genes MEN1, VHL, NF1, and TSC1 or TSC2, respectively.