The discovery of TDP-43, a nuclear RNA-binding protein (RBP), identified the importance of RNA biology in ALS pathogenesis and led to identification of several other RBPs including FUS [2, 33, 44], TAF15 [27, 55], hnRNPA1 [13, 16, 17, 26, 61], hnRNPA2B1 [29], EWS [42], and MATR3 [23]. Here, MATR3 is linked to amyotrophic lateral sclerosis.