P2RX4 and ischemic stroke: Enhances the proinflammatory function of monocytes via P2X4R and promotes long‐term recovery of ischemic stroke. CCL2 promotes leukocyte crossing of the BBB and alters the expression of TJs in BMECs. CCL2/CCR2 binding induces conformational changes in VLA‐4. CCR2+ monocytes express high levels of VEGF‐A and can mediate the expression of PDGF beta and PDGF receptor beta mRNA in the ischemic state