CYP2B6 and memory impairment: Similarly and slightly more efficient than E2 injection (the improvement of escape time by E2 administration was ~86% by BSMCs), BMSCs transplantation reversed the memory impairment induced by OVX (*P < 0.05 versus OVX group, Fig. 3B), however, siRNA knockdown of P450 in BMSCs largely abolished their improvement on learning ability (Fig. 3A–C).