RAC1 and ischemic stroke: The Rac1/MLCK signaling pathway is downstream of the P2Y6 signaling cascade in radiation injury model.19 Our result showed that the level of Rac1 expression did not differ between the MRS2578 and saline group, suggesting that Rac1 signaling was not involved in microglia phagocytosis after ischemic stroke (Figure S1).