On the one hand, exosomes secreted by NSCs can carry specific particles from the original cells to target cells, leading to increased pathological changes, such as amyloid β-protein (Aβ) and tau protein β in Alzheimer’s disease (AD), prion proteins in spongiform encephalopathy and α-synuclein in Parkinson’s disease (PD). This evidence concerns the gene PRNP and Alzheimer disease.