NF1 and von Hippel-Lindau disease: NENs, particularly well-differentiated, slow-growing tumors (NETs), can also occur in the context of hereditary syndromes, including multiple endocrine neoplasia type 1 (MEN1), von Hippel–Lindau syndrome (VHL), and neurofibromatosis 1 (NF-1), which is often linked to PanNETs [15].