An increase of classical and a decrease of non-classical monocytes was observed not only in sALS and fALS patients, in line with findings in the mutant hSOD1 mice, but also in pre-symptomatic ALS mutant carriers (Butovsky et al., 2012; Zondler et al., 2016), suggesting that this phenotype is an early event in the pathology. Here, SOD1 is linked to amyotrophic lateral sclerosis.