IL6 and Parkinson disease: Entrance of pro-inflammatory cytokines; tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) has been shown to be associated with the progression of Parkinson’s disease (Smith et al., 2012), Alzheimer’s disease (Minagar et al., 2002), and schizophrenia (O’Brien et al., 2008; Al-Amin and Reza, 2014).