Expression of mutant SOD1 in neurones did not result in ALS symptoms.559 In contrast, silencing of this gene in astrocytes in global SOD1 expressing mice with ALS-like symptoms, arrested pathological progression.560,561 Similarly, grafting astrocytes hosting SOD1G93A mutant into the spinal cord of the healthy mice promoted motor neurones demise resulting in ALS symptoms.562 At the same time transplanting healthy astrocytes into the spinal cord of globally SOD1G93A mutant expressing rats delayed pathological progression.563. The gene discussed is SOD1; the disease is amyotrophic lateral sclerosis.