SOD1 and familial amyotrophic lateral sclerosis: Of note, NEDL1 can bind and ubiquitinate mutant superoxide dismutase-1 (SOD1), the causal protein of familial amyotrophic lateral sclerosis (FALS), as results in the formation of potentially cytotoxic protein that aggregates in the spinal cord and consequent motor neuron death in FALS [72].