Neurofibromatosis type 1 (NF1) is a common autosomal dominant genetic disorder characterized by mutations in NF1, associated with almost universal development of cutaneous neurofibromas, as well as plexiform neurofibromas, optic pathway glioma (OPG), and malignant peripheral nerve sheath tumors. The gene discussed is NF1; the disease is plexiform neurofibroma.