The pathologically relevant NH2tau 26–44aa stretch, which is the minimal active moiety of a neurotoxic 20–22 kDa NH2-derived tau peptide (aka NH2htau), accumulates at Alzheimer’s disease pre-synaptic terminals (Amadoro et al., 2006, 2010, 2012; Corsetti et al., 2015) and is present in CSFs from living patients suffering from Alzheimer’s disease and other non-Alzheimer’s disease neurodegenerative diseases (Amadoro et al., 2014). This evidence concerns the gene MAPT and Alzheimer disease.