Multiple clinical and experimental studies have shown compelling evidence that complement activation is involved in the pathogenesis of ALS, whereby components of all the complement pathways are upregulated in the serum, cerebrospinal fluid, skeletal muscles and neurological tissue (spinal cord and motor cortex) of ALS patients, as well as in transgenic SOD1 animal models of ALS [8]. Here, SOD1 is linked to amyotrophic lateral sclerosis.