The association of several of the candidate biomarkers with AD pathophysiology has already been probed, most notably for cystatin C, which appears to play a role in preventing Aβ oligomerization and amyloidogenesis [66]–[70], and to a lesser extent for PAI-1 [71]–[73], MIF [45], [74], fibrinogen [75], [76], FAS and FASL [77]–[80], VEGF [81]–[83], and TNF RII [84]–[86]. Here, CST3 is linked to Alzheimer disease.