CXCL8 and Parkinson disease: Specifically, enhanced levels of cytokines such as tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), interleukin 6 (IL-6), interleukin 10 (IL-10), and interleukin 8 (IL-8) have been found in PD patients when compared with healthy controls [82,83,84].