YBX1 and Alzheimer disease: In summary, we demonstrated that exosomal miR-223 mediated the cross-talk between AD cell model and microglia, that the protect properties of microglia-derived EXO due in part to the delivery of miR-223 to AD model in vivo and in vitro. Mechanistically, we identified an unsuspected role for YB-1 in determining EXO cargo specificity, like sorting miR-223 into EXO.