ALS and FTLD overlap clinical and neuropathological characteristics, and both are relevant to C9orf72 amplification and RBP gene variants (TDP-43, FUS, ATXN2, EWSR1, TAF15, HNRNPA1, HNRNPA2B1, TIA1, and MATR3) [135, 144, 145]. This evidence concerns the gene ATXN2 and amyotrophic lateral sclerosis.