Using multiplexed immunoassay platform (Meso Scale Discovery), we observed that IL-8 concentration in the media from vehicle-treated prodromal PD monocytes was significantly reduced relative to other groups (Supplementary Fig. 1A), however absolute concentrations of TNF, IL-1β, and IL-10 were not significantly affected by PD status (Supplementary Fig. 1B–D). Here, IL1B is linked to Parkinson disease.