Molecular Biomarkers of Disease for Diagnosis and Drug Development

Most biomarkers are serendipitously discovered as upregulated transcripts in specific conditions associated with the disease. From the discovery of a candidate biomarker to the development of a ready-to-use biomarker has to go through several steps, including qualification, verification, research assay, optimization, and validation. Final biomarker validation includes a number of different tests to pass, namely sensitivity, specificity, analytical validity, and clinical validity. At the end of this long process, biomarkers for clinical use have to be by definition objective, quantifiable characteristics of biological processes.