We demonstrate that (1) the number of Ly-6Chigh MMs in the spleen was significantly increased at 4 h after cerebral ischemia, which is correlated with increased expression of the proinflammatory monocyte markers (Ly-6C and CCR2) in isolated splenocytes from ischemic mice, and (2) these ischemia-induced effects were almost completely prevented by αCD147 treatment 1-h prior to ischemia onset. This evidence concerns the gene CCR2 and ischemia.