Neurofibromatosis type 1 is a common genetic disease with a broad spectrum of clinical manifestations in multiple organs of the body, including the development of tumors and cancers. In animal models of this disease, dysfunction in a part of the cell called mitochondria ,which is responsible for energy production, was seen. This project will study the function of mitochondria in patients with neurofibromatosis through serial blood samples and compare it with people not afflicted by neurofibromatosis. With that, we plan to confirm If there is mitochondrial dysfunction in patients, and if the degree of dysfunction correlates with symptoms like pain and fatigue. Also, we will study if mitochondrial dysfunction is a marker for toxicity of medications like MEK inhibitors that patients with neurofibromatosis type 1 use in a daily basis.