Wildtype PA28γ overexpression improved cell survival in excitotoxic and proteasome-inhibited states in a neuronal model of HD (Seo et al., 2007), and lentiviral-delivered gene therapy increasing PA28γ expression improved motor coordination in mouse models of HD and reduced ubiquitin-positive inclusion body expression, although the decrease in mHTT in inclusion bodies was not significant (Jeon et al., 2016). This evidence concerns the gene PSME3 and Huntington disease.