FOXO3 and amyotrophic lateral sclerosis: The activation of FoxO was essential for the muscle atrophy induced by denervation or fasting, and activated FoxO3 caused coordinately activating ubiquitin–proteasome system (UPS) and autophagy–lysosomal system (ALS), especially lysosomal proteolysis, in denervation- or fasting-induced muscles atrophy (Zhao et al., 2007; Zhao et al., 2008).