As for AD, (1) the administration of GDNF protects against aluminum-induced apoptosis in rabbits by up-regulating Bcl-2 and Bcl-XL and inhibiting mitochondrial Bax translocation [36]; (2) Lenti-GDNF gene therapy protects against AD-like neuropathology in 3xTg-AD mice [37]; and (3) the level of mature GDNF peptide is down-regulated in the postmortem middle temporal gyrus of AD patients [38]. This evidence concerns the gene GDNF and Alzheimer disease.