TARDBP and amyotrophic lateral sclerosis: These optogenetic TDP-43 effectively displayed clustering upon blue light illumination, leading to cytoplasmic deposition of TDP-43 aggregates with the pathological signature of S409/S410 phosphorylation typically detected in degenerating motor neurons in ALS (Mann et al., 2019; Zhang et al., 2019), suggesting that the optogenetically induced TDP-43 aggregation mimics at least some of the TDP-43 pathology occurring ALS.