The role of the complement cascade has been demonstrated in patients and animal models of myasthenia gravis, an autoimmune disease affecting neuromuscular transmission.64 Preclinical and clinical studies have confirmed the efficacy of the complement inhibitor Eculizumab, an antibody directed towards C5, which has been recently approved for the treatment of AChR antibody-positive generalised myathenia gravis.65 Therapeutic inhibition of the complement system has been shown to be useful also in other neurological diseases. The gene discussed is C5; the disease is autoimmune disease.