Across studies, elevated levels of pro-inflammatory cytokines such as IL-2, IL-6, IL-8, TNF-α, and IFN-γ have been reported in the blood of PD patients, with cytokine concentrations correlating with clinical stage and disease progression (Reale et al., 2009; Garretti et al., 2019). The gene discussed is IFNG; the disease is Parkinson disease.