On the one hand, exosomes derived from damaged nerve cells can transfer amyloid precursor protein (APP), γ/β-secretase, Aβ peptide, C-terminal APP and tau protein to adjacent healthy neurons to accelerate the death of peripheral neurons, thus leading to the spread of pathological features of AD (Perez-Gonzalez et al., 2012; Sardar Sinha et al., 2018). Here, MAPT is linked to Alzheimer disease.