We measure the production of NLRP3 inflammasome and polarization of microglia/macrophages in MCAO mice treated by meisoindigo or MCC950, a selective inhibitor of the NLRP3 inflammasome, and find that MCC950 shifts microglia/macrophages from the pro-inflammatory M1 to the tissue-reparative and anti-inflammatory M2 phenotype 3 days after ischemic stroke. The gene discussed is NLRP3; the disease is ischemic stroke.