BDNF and Alzheimer disease: The data showed that engrafted cells with BDNF overexpression were still able to ameliorate the cognitive deficits of AD mice in the MWM test (Supplementary Fig. S6a,b) and the NOR test (Supplementary Fig. S6c), but the engrafted control cells lost their therapeutic potential, suggesting the importance of BDNF for achieving the long-term therapeutic goal.