CST3 and Alzheimer disease: When compared with AD; beta‐secretase‐1 (BACE1), cystatin C (CST3), GDP‐dissociation inhibitor‐1 (GDI1), insulin‐like GF‐binding protein‐7 (IGFBP7), IL15, pleiotrophin (PTN), and synaptosomal‐associated protein 25 (SNAP25) had lower odds for the FTD group.