CCL5 and Parkinson disease: While certain cytokines, chemokines, and other inflammatory indicators in PD patients’ peripheral blood exhibit irregularities, dysregulated variables such as IL-6, TNF, IL-2, IL-10, CRP, and CCL5 are frequently found (Qin et al., 2016; Qu et al., 2023), reinforcing the evidence of inflammation-related clinical manifestations in PD.