Clinical studies observed higher levels of pro-inflammatory factors such as interleukin (IL)-1beta, IL-2, tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, and cluster of differentiation (CD)4+ and CD8+ T lymphocytes in PD brains (Dobbs et al., 1999; Hisanaga et al., 2001; Reale et al., 2009). The gene discussed is TNF; the disease is Parkinson disease.