No difference was found in DR expression in TCM and TEM between PD patients and HS, except for DR D3+ TCM which were higher in PD patients in terms of percentage of total CD4+ T cells, and for DR D4+ TEM which were higher in PD patients in terms of both absolute numbers and percentage of total CD4+ T cells (see Supplementary Fig. S1 and S2). Here, CD4 is linked to Parkinson disease.