Notably, elevated levels of cytokines, including IL-1β, IL-2, IL-6, IFN-γ, and TNF-α, as well as CD4+ lymphocyte counts, have been detected in the serum and cerebrospinal fluid of PD patients (Brodacki et al., 2008; Reale et al., 2009). The gene discussed is IFNG; the disease is Parkinson disease.