Aberrant CatB activation is correlated with motor neuronal death in sporadic ALS cases23 and the SOD1G93A mice model.24 We showed that inhibition of CatB activity by CysC was also essential for its neuroprotective activity (Figure 7), supporting the idea that aberrant proteolysis mediated by CatB is highly toxic to motor neurons. This evidence concerns the gene TYRP1 and amyotrophic lateral sclerosis.