Interestingly, we found an increase of the pro-inflammatory cytokines IL-2, IL-6, and TNFα as well as of the pro-migratory chemokine MCP-1 (monocyte chemoattractant protein-1) in the CSF of PD patients, whereas anti-inflammatory IL-9 was decreased (Figure 3 A+B, only detected cytokines and chemokines shown). This evidence concerns the gene IL2 and Parkinson disease.