NF1 and neoplasm: Neurofibromin (Nf1) is encoded by NF1 gene which has been identified as a tumor suppressor gene involved in Neurofibromatosis type I. Neurofibromatosis type I (NF1), also known as von Recklinghausen disease, is an autosomal dominant disorder and one of the most common genetic diseases as it affects 1 individual in 3,500.