NEFL and Alzheimer disease: This is noteworthy because down-regulation of NF-L expression is a characteristic feature of the limbic system in AD and accompanies the atrophy of neurons and progressive loss of neuronal architecture and synaptic contact in the AD brain (McLachlan et al., 1988; Lukiw et al., 1990; Julien and Mushynski, 1998; Clement et al., 2016; Khalil et al., 2018).