Development and Validation of Patient Reported Outcome (PRO) Measures for Individuals With Neurofibromatosis 1 (NF1) and Plexiform Neurofibromas (pNFs)

* SUBJECT INCLUSION CRITERIA: * Documented NF1 either by NIH clinical criteria or molecularly-proven mutation in the NF1 gene, PER the Neurofibromatosis Diagnostic Criteria AND \>=1 plexiform neurofibroma in any location that is either symptomatic or asymptomatic, and is defined by the following: 1. a neurofibroma that has grown along the length of a nerve and may involve multiple fascicles and branches OR a spinal neurofibroma that involves two or more levels with connection between the levels or extending laterally along the nerve OR a skin thickness neurofibroma; 2. measures \>=3 cm on longest diameter by visual exam, palpation or 2D MR imaging OR \>=3 mL by volumetric MR imaging. * For phase 1, Age \>=5 years. (complete) * For phase 2, Age \>= 8 years * Ability of subject or parent or guardian to understand and the willingness to sign a written informed consent document. * Participants must be able to understand, read, and speak the English language. * For phase 1 focus groups only, patients need to report experiencing pNF related pain recently with a minimum pain level of 3 on the current NRS-11 or report taking prescription medication that reduces pain and experiencing pNF related pain recently with a minimum pain level of 1 on the current NRS-11. (complete) * For phase 2 patients with pain, patients need to report recently experiencing at least a minimal amount of pNF-related pain. Specifically, they will be asked if they recently experienced any pain in a target tumor area and will have to respond yes to be eligible. * For phase 2 patients without pain, patients need to report no recent pNF-related pain. Specifically, they will be asked if they recently experienced any pain in a target tumor area and will have to respond no to be eligible. PRIMARY CAREGIVER INCLUSION CRITERIA: * Primary caregiver (i.e. parent,guardian, grandparent) who is \>= 18 years old of participating subject \<= 17 years old * Participants must be able to understand, read, and speak the English language EXCLUSION CRITERIA: * Patients with severe cognitive or behavior impairments who, in the judgment of the investigators, would not be able to cooperate with the study procedures will be excluded. * Patients cannot be newly enrolled on a clinical trial to treat their pNF or cannot have started a new pain treatment regimen (e.g., medication, psychosocial therapy, physical therapy, etc.) at the time of enrollment. Specifically, patients will be ineligible if they were enrolled on a MEK inhibitor trial in the past 12 months or began a new pain medication or treatment within the past 3 months prior to enrollment on this study.