CCL2 and Parkinson disease: However, one study failed to find significant differences in CSF levels of the inflammatory markers C-reactive protein (CRP), IL-6, TNF-α, eotaxin, interferon gamma-induced protein 10 (IP-10), monocyte chemotactic protein 1 (MCP-1), and macrophage inflammatory protein- (MIP-) 1β from PD patients in comparison with a reference group [33].