These mice express a high copy number of the human G93A mutant SOD1, and recapitulate many key features of the human ALS phenotype, like adult disease onset, selective motor neuron degeneration and axonal loss (Gurney et al., 1994; Chiu et al., 1995; Fuchs et al., 2010). Here, SOD1 is linked to amyotrophic lateral sclerosis.