The authors could demonstrate that parkinsonism cases, defined as those subjects having the highest scores at the Unified Parkinson Disease Rating Scale (UPDRS3), showed a significant inverse association between methylation in the gene coding for iNOS in humans, NOS2, and parkinsonism prevalence compared to controls, specifically at CpG site 8329 located in an exonic splicing enhancer of NOS2. Here, NOS2 is linked to Parkinsonism.