UPF1 and amyotrophic lateral sclerosis: Indeed, overexpression of UPF1 in FUS-ALS models suppresses the observed neurotoxicity (Ju et al., 2011; Barmada et al., 2015), however overexpression of UPF1 did not reduce the presence of FUS inclusions, bringing into question whether these inclusions exhibit a toxic effect (Ju et al., 2011).