Accordingly, in spite of ALS being a neurodegenerative disease characterized by upper and lower motor neuron degeneration, it has been recently found to have a sensory neuropathy component observed in up to 20% of ALS human patients, pain among them, affecting unmyelinated small and myelinated large fibers as part of the process of primary neurodegeneration [355,356], potentially leading to neuropathic pain, and relevant to understand the full spectrum of ALS, associated with SOD1 mutation. The gene discussed is SOD1; the disease is amyotrophic lateral sclerosis.