CD99 and Alzheimer disease: Comparative analysis identified 56 significantly differentially-expressed proteins between groups. Fourteen of these aligned with the previous findings. Novel proteins reported include calsyntenin-3, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor, CD99 antigen, di-N-acetyl-chitobiase, and secreted phosphoprotein-1. Protein expression changes in symptomatic and asymptomatic mutation carriers overlapped with those seen in late-onset AD.