Increased expressions of cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6), and transforming growth factor-β1 (TGF-β1), have been observed in PD (Boka et al., 1994; Allen Reish and Standaert, 2015). The gene discussed is TNF; the disease is Parkinson disease.