SOD1 and amyotrophic lateral sclerosis: The fact that the upregulation of mutSOD1 in the SOD1G93A ALS mouse model can influence the beneficial effect of melatonin raises the possibility that this animal model may not be ideal for assessing the neuroprotective properties of melatonin or other molecules with complex antioxidative properties because ALS progression does not always involve SOD1 mutation.