This microglia-induced A1 astrocytic subtype is characterized by increased expression of complement component 3 (C3) and has been identified in human patients and mouse models of Alzheimer’s disease (AD), Huntington’s disease, amyotrophic lateral sclerosis, multiple sclerosis, Parkinson’s disease, prion disease and frontotemporal dementia6,8–10. This evidence concerns the gene C3 and amyotrophic lateral sclerosis.