APP and Alzheimer disease: To investigate the effects of OCYYoung‐EVs and OCYAged‐EVs on the process of AD in vivo, 4‐month‐old WT or APP/PS1 mice were intravenously administered equal amounts (2.4 × 106 particles per gram of body weight) of OCYYoung‐EVs, OCYAged‐EVs, or solvent once a week for eight weeks (Figure4A).