For example, the expression of synaptic proteins, such as SNAP25, GAP43, and neurogranin, in the plasma-derived EVs of patients with preclinical AD is lower than that in healthy controls31, and the expression of SNAP25 in serum-derived EVs is positively correlated with age- and education-corrected MMSE scores36. This evidence concerns the gene SNAP25 and Alzheimer disease.