The PDGene meta-analysis in the website (http://www.pdgene.org) demonstrated that the Y allele of UCHL1  S18Y SNP was significantly inversely related to PD using data from a total of 26 case–control samples; however, such a significant association was not observed using data from 12 case–control Asian samples [33]. This evidence concerns the gene UCHL1 and Parkinson disease.