SG component proteins with a causal role for motor neuron diseases include TDP-43 (gene symbol TARDBP) [20–23], FUS [24–26], ATXN2 [27–29], SMN [30, 31], Tau (gene symbol MAPT) [32, 33], HNRNPA2B1, and HNRNPA1 [34]. This evidence concerns the gene ATXN2 and motor neuron disorder.