This is underscored by identified ALS and FTD mutations in genes that encode proteins involved in RNA metabolism including FUS, TARDBP, ataxin 2 (ATXN2), and T-cell intracellular antigen 1 (TIA1) (Ross et al., 2011; Takada, 2015; Brown and Al-Chalabi, 2017; Hofmann et al., 2019; Rubino et al., 2019). Here, ATXN2 is linked to amyotrophic lateral sclerosis.