Subsequent quantitative analysis using Tim4 (T Cell Immunoglobulin and Mucin Domain-containing Protein 4)-based sandwich enzyme-linked immunosorbent assay (ELISA) revealed that platelet marker (CD41, CD61)-positive EVs as well as tetraspanin (CD63 and CD9)-positive EVs are significantly increased in sera of patients with AD than those of HCs. The gene discussed is CD63; the disease is Alzheimer disease.