Measuring Biomarker Progress.

A biomarker has been defined as "a characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic process, or pharmacologic responses to a therapeutic intervention." This comprehensive definition of biomarkers arose from the April 1999 US Food and Drug Administration (FDA)/National Institutes of Health consensus conference on "Biomarkers and Surrogate Endpoints: Advancing Clinical Research and Applications," and emphasized that biomarkers are medical measurements, including physiological measurements, blood tests, molecular analyses of biopsies, genetic or metabolic data, and measurements from images. Research on biomarkers-organized and propelled by this definition-has skyrocketed, with over 200,000 PubMed citations in the last five years.