Impairments in BDNF synthesis have been associated with the hallmarks of neurodegenerative pathogenesis [10]: a lack of BDNF has been selectively observed in neurons containing neurofibrillary tangles in AD [11], and a loss of BDNF production has been associated with mutations of alpha-synuclein in early-onset familial PD [12]. The gene discussed is BDNF; the disease is Alzheimer disease.