As a tumor-suppressive gene, NF1 gene mutations are linked not only to neurofibromatosis type 1 but also to juvenile myelomonocytic leukemia (OMIM: 607,785), familial spinal neurofibromatosis (OMIM:162,210), and Watson syndrome (OMIM: 193,520), etc. [15, 16]. This evidence concerns the gene NF1 and neurofibromatosis type 1.