By immunofluorescence, compared with AD-PBS mice, the hyperreactive microglia (IBA1+, INOS+) in the hippocampus were significantly decreased and M2 microglia marker expression (IBA1+, Arg1+) increased after 5 weeks of hDPSCs transplantation, suggesting that the administration of hDPSCs promoted the M2 polarization of microglia, which contributes to the clearance of Aβ and neuroinflammation in the AD mice brain (Figs. 7a, c, and S8a, b). This evidence concerns the gene ARG1 and Alzheimer disease.