The genome-wide association study published in Nature Genetics was conducted by the NeuroGenetics Research Consortium, an international team of researchers led by Haydeh Payami. The finding of association of the immune regulating genes (HLA) with Parkinson’s disease, and its subsequent validation world-wide, cemented the role of the immune system in the root of Parkinson disease, opening the gates to a now very active field in PD research. The discovery suggests some forms of Parkinson’s disease could be triggered by infectious agents or unknown factors that send the immune and inflammatory response into overdrive.