For example, numerous proinflammatory cytokines and factors such as tumor necrosis factor (TNF)-α, β2-microglobulin, epidermal growth factor (EGF), transforming growth factor α (TGFα), TGFβ1, and interleukin (IL)-1β, IL-6, and IL-2 were found in the striatum of PD patients (78). Here, TNF is linked to Parkinson disease.