Table 2. The criteria of an ideal biomarker for clinical use.
| Diagnostic biomarkers: c>a>b>e>d>f |
| Disease activity biomarkers: b>f>a>e>d |
| Treatment-response biomarkers: f>b>a>e>d |
a, a high specificity; b, a reliable sensitivity; c, detectable in AD early; d, inexpensive and user-friendly; e, non-invasive or well-accessible; f, available in monitoring the progression.