Ragland et al. [5] conducted a meta-analysis of published case–control studies concerning the UCHL1  S18Y variant and Parkinson’s disease (PD), which indicated a significant inverse association between the Y allele and PD under a recessive model using data from studies in populations of Asian ancestry and a similar significant inverse relationship under a dominant model using data from studies in populations of European ancestry. Here, UCHL1 is linked to Parkinson disease.