CD4 and Parkinson disease: Here, to address the cell type associated with IL-10 production, 20 PD donors were stimulated in vitro with an α-syn epitope pool for 2 weeks, and then the production of IFNγ, IL-4, and IL-10 along with the lineage-specific markers CD56, CD19, CD14, CD3, CD4, and CD8 was analyzed by flow cytometry.