CCR2 and Parkinson disease: In addition, they also found that α-Syn induced a robust infiltration of CCR2+ peripheral monocytes into the SN, whereas deletion of CCR2 can prevent α-Syn-induced monocyte entry, attenuate MHCII expression, and decrease degeneration of dopaminergic neurons, suggesting that extravasation of pro-inflammatory peripheral monocytes into the CNS play an important role in neuroinflammation and neurodegeneration in PD [122].