immune system involved in defending against all the foreign pathogens through complement fragments that participate in opsonization, chemotaxis, and activation of leukocytes and through cytolysis by C5b- 9 membrane attack complex. The complement (C) system has been implicated as a factor in the causation or propagation of tissue injury in central and peripheral nervous system disorders. Complement factors play a predominant role in nerve injury, inflammation and repair, thus playing part in neurodegeneration, neuroinflammation and neuroprotection. 

Keywords: Immunology; Neuroimmunology; Immunogenetics; Genetic neurology; Complement system.