To understand the therapeutic potential of engrafted NSCs with or without BDNF overexpression, we stereotactically transplanted both kinds of NSCs into the hippocampus of 16-month-old Tg2576 mice (referred to as Tg+BDNF-NSCs and Tg+Control-NSCs mice), a transgenic mouse model of AD with a Swedish form of the amyloid precursor protein mutation22. The gene discussed is BDNF; the disease is Alzheimer disease.