Focusing on human synaptosomes, Fein et al. (Fein et al., 2008) and Sokolow et al. (Sokolow et al., 2012) identified hyper-phosphorylated tau in FACS-sorted Alzheimer’s disease synaptosomes, particularly those isolated from the entorhinal cortex and hippocampus, which partially co-localised with amyloid beta (Aβ). This evidence concerns the gene MAPT and early-onset autosomal dominant Alzheimer disease.