IL6 and Parkinson disease: Cytokines such as IL-1β, IL-2, IL-4, IL-6, TNFα, transforming growth factor (TGF)α, and TGFβ1 were also increased at the protein level in the striatum, and in the ventricular and lumbar cerebrospinal fluid of PD patients (Vawter et al., 1996; Nagatsu et al., 2000).