NGF and Alzheimer disease: During development about half of neurons die due to lack of target-derived trophic support such as caused by limiting supplies of NGF.1 In AD, a major cause of neuron degeneration is thought to be due to oligomerization and accumulation of β-amyloid (Aβ) protein.2–6 Alterations of NGF metabolism and signaling are also implicated in AD.7,8 However, the mechanisms of neuron death in the absence of NGF or in response to oligomeric Aβ remain incompletely understood.