TNF and Parkinson disease: Meanwhile, increased levels of pro-inflammatory cytokines were observed in the brain, cerebrospinal fluid, and blood of PD patients, especially tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-2, IL-6, IL-8, and interferon-γ (IFN-γ) (Dzamko et al., 2015; Marogianni et al., 2020; Figure 1).