In the cerebrospinal fluid and striatum of PD patients, the increment of cytokine levels, such as T-cell activation-associated cytokine (IL-2), proinflammatory cytokines (TNF-α, IL-1β, and IL-6), anti-inflammatory cytokine (IL-4), and several growth factors (EGF and TGF-β1), is the main feature of inflammation-induced processes [77, 78]. Here, IL6 is linked to Parkinson disease.