For example, intermediate repeat lengths in ataxin 2 (ATXN2) (Elden et al., 2010; Van Damme et al., 2011) and mutations in heterogeneous nuclear ribonucleoprotein A1 and A2B1 (hnRNPA1/A2B1) (Kim et al., 2013) are linked to ALS. Here, ATXN2 is linked to amyotrophic lateral sclerosis.