However, the pathogenesis of ALS is multifaceted, and it is difficult to say how TDP-43 differs from other related genetic risk factors for ALS (such as SOD1, FUS and C9orf72) or which of these risk factors is the dominant one (Allen et al., 2019; Richardson et al., 2013). Here, C9orf72 is linked to amyotrophic lateral sclerosis.