Since then, mutations impacting additional RBPs, including FUS, hnRNP A1, hnRNP A2B1, matrin-3 (MATR3), and TIA1, were identified that are causative of ALS, FTD, and/or IBM (Kwiatkowski et al., 2009; Vance et al., 2009; Kim et al., 2013; Liu et al., 2013; Johnson et al., 2014; Mackenzie et al., 2017). Here, MATR3 is linked to frontotemporal dementia.