Changes in EV cargo have been observed in a number of neurodegenerative diseases, including Parkinson’s disease, where EVs have been shown to carry α-synuclein between cells, transferring the disease between neurons [169]; in prion diseases where EVs have been shown to transfer prion proteins between neurons [170]; and in AD, where EVs seem to be a site of APP processing and have been shown to contain phosphorylated tau [171,172]. Here, APP is linked to Alzheimer disease.