FUS and amyotrophic lateral sclerosis: The loss of Gems seen in motor neurons of ALS patients (Fig 3), coupled with the fact that eliminating TDP-43 from mouse neurons in vivo leads to the loss of Gems (Shan et al, 2010), clearly supports our findings that TDP-43 and perhaps FUS/TLS is important for Gem formation and U snRNPs biogenesis, as observed before in a similar way with SMN.