For example, inflammatory cytokines including interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) and additionally, reactive oxygen species (ROS) and inducible nitric oxide synthase (iNOS) were increased in cerebrospinal fluid of PD patients, which could further impact on neurons to induce progressive neurodegeneration (Montgomery and Bowers 2012; Blum-Degen et al. 1995). The gene discussed is NOS2; the disease is Parkinson disease.