Brain-derived neurotrophic factor (BDNF) is one of the most important neurotrophic factors in the central nervous system, which can play neuroprotective and reparative roles; notably, neuroinflammation in AD can be inhibited and cognitive deficits can be counteracted through up-regulation of the BDNF/TrkB mechanistic pathway [33]. Here, BDNF is linked to Alzheimer disease.