These differences are exemplified by Vapb and Ubqln2 KI models that have been valuable to study potentially impaired autophagy and proteasomal degradation mechanisms in ALS pathogenesis, but which do not develop the motor impairment or MN loss that can arise in their transgenic counterparts (Table 1D,E). This evidence concerns the gene UBQLN2 and amyotrophic lateral sclerosis.