Importantly, pathological comparisons between sporadic and inherited cases have revealed a common biochemical signature of ubiquitinated lesions containing TAR DNA binding protein (TDP-43) [1, 44], with the appearance of TDP-43-positive inclusions in almost all ALS cases, except in those caused by mutation in SOD1 or FUS [36, 56]. Here, SOD1 is linked to amyotrophic lateral sclerosis.