It is has been suggested that brain-derived neurotrophic factor (BDNF) signaling, one of the major pathways responsible for endogenous neuroprotection, is dramatically disrupted in AD (Phillips et al., 1991; Connor et al., 1997; Ferrer et al., 1999; Arancibia et al., 2008; Zuccato and Cattaneo, 2009; Diniz and Teixeira, 2011; Kemppainen et al., 2012; Nagahara et al., 2013; Jerónimo-Santos et al., 2015). The gene discussed is BDNF; the disease is Alzheimer disease.