SPP1 and Alzheimer disease: siRNA-KIAA1199 hBMSC exhibited reduced levels of AKT and ERK phosphorylation (P-AKT, P-ERK) following AD induction (Fig. 7g and Fig. S23e); while knocking down of OPN (siR-OPN) led to opposite effects with enhanced of P-AKT and P-ERK (Fig. 7g and Fig. S23f).