In a seminal study of Mori et al. in 2005, the ubiquitin-like protein NEDD8 (neural precursor cell expressed developmentally downregulated 8 protein) was found to be involved in the generation of ubiquitinated aggregates in the α-Synucleinopathy brain, not only of PD and DLB cases, but also of MSA patients, thus suggesting that the UPS may also exert a significant role in the formation of αSyn-positive aggregates in α-Synucleinopathies in general [88]. This evidence concerns the gene HMBS and Parkinson disease.