Amyotrophic lateral sclerosis (ALS), partly caused by the mutations and aggregation of human copper, zinc superoxide dismutase (SOD 1), is a fatal degenerative disease of motor neurons.Because SOD1 is a major copperbinding protein present at relatively high concentration in motor neurons and copper can be a harmful pro-oxidant,we want to know whether aberrant copper biochemistry could underlie ALS pathogenesis.