2. Diagnosis: Patients who are diagnosed with NF1 using the NIH Consensus Conference criteria or have a confirmed NF1 mutation with analysis performed in a CLIA-certified laboratory. NF1 mutation testing to confirm eligibility will not be performed on this protocol, but as part of a separate screening study. Histologic confirmation of NF1 related benign tumors is not necessary in the presence of consistent clinical and radiographic findings, but is required for individuals with MPNST who enroll on this study.