Although many serum biomarkers were discussed, only a few are FDA approved for disease diagnosis and prognosis, including cancer biomarkers in human serum, CEA, Her-2/neu, bladder tumor antigen, thyroglobulin, alpha-fetoprotein, PSA, CA125, CA19.9, CA15.3, and some other cancer biomarkers, as well as cardiovascular disease biomarkers Troponin I and B-type natriuretic peptide (for more detailed review, see Polanski and Anderson, 2006). Here, AFP is linked to cancer.