CHST15 and Alzheimer disease: These proteins formed five major clusters: (1) proteins more abundant in Aβ+/tau- AD than in the other two groups (e.g. SSC5D and CHST15); (2) proteins with lower abundance in the Aβ+/tau- AD than in the other two groups, (e.g. MGFEB and GALNT2); (3) proteins with higher abundance in non-AD controls; (4) proteins enriched in Aβ+/tau + AD, such as tau (MAPT) and the 14-3-3 proteins (e.g. YWHAE, YWHAZ, and YWHAZ); and (5) proteins reduced in Aβ+/tau- AD but elevated in controls (e.g. MLEC and LY6H).