IL-6 can have both proinflammatory and anti-inflammatory effects, and its role in PD remains controversial.18, 19, 20, 21, 22, 57, 58 However, MPTP treatment upregulated the proinflammatory markers IFN-γ and TNF-α and downregulation of the anti-inflammatory markers TGF-β1 and IL-10 in the periphery and the CNS, which suggests that MPTP induces a proinflammatory profile. This evidence concerns the gene TNF and Parkinson disease.