Therefore, our study used 846 cognitively normal individuals from the Chinese Alzheimer’s Biomarker and LifestylE (CABLE) study to (1) explore the relationship between B2M levels and cognition, (2) delve into the relationship between B2M levels and CSF AD biomarkers, and (3) investigate whether the effects of B2M levels on cognitive function are mediated through AD core pathology. This evidence concerns the gene B2M and Alzheimer disease.