However, it is pertinent to note that although some cuproenzymes appear unsatiated for their physiological copper requirement in mutant SOD1 mice and human cases of ALS, total copper content of spinal cord tissue is not decreased, and some reports describe an overall increase in spinal cord copper.9–15 Furthermore, treatment with the copper ligating compound ammonium tetrathiomolybdate has also been reported to protect motor neurons and slow the rate of decline in motor function in ALS model mice.14 These reports on copper in ALS span sporadic human cases and numerous SOD1 animal models. This evidence concerns the gene SOD1 and amyotrophic lateral sclerosis.