In ALS caused by mutations in FUS/TLS (FUS-ALS), the cytosolic mislocalization of FUS disrupts the normal interaction between U1 snRNP and SMN complexes, which leads to perturbed snRNP assembly and RNA splicing in FUS-ALS (Jutzi et al, 2020; Sun et al, 2015a). This evidence concerns the gene SMN2 and amyotrophic lateral sclerosis.