SOD1 and amyotrophic lateral sclerosis: In addition to motor neuron loss and paralysis, evidence of reactive microglia/macrophages and astrocytes is observed in motor regions of the CNS in sporadic and familial amyotrophic lateral sclerosis (ALS) [1,2], as well as in the ALS animal models of transgenic mice and rats expressing human mutant SOD1 (hmSOD1) [3-7].