IL6 and Parkinson disease: Elevated levels of cytokines such as interleukin (IL)-1beta, IL-6, IL-18, and tumor necrosis factor (TNF)-alpha have been detected in the CSF of PD patients compared to controls.8–10 Additionally, increased levels of cytokines such as TNF-alpha, IL-1 beta, IL-6, and IL-10 in the serum or plasma of PD patients have also been reported, suggesting systemic immune dysregulation in PD.11–13