It is a characteristic that is objectively measured and evaluated as an indicator of normal biological processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention. A biomarker (biologic marker) is a measurable indicator of a specific biological state, particularly one relevant to the risk for, the presence of, or the stage of the disease. Although historically the term often referred to a physical trait or physiological metric, it now typically refers to products of genomic, metabolomics, and proteomic research. Biomarkers can be used clinically to screen for, diagnose, or monitor the activity of diseases and to guide molecularly targeted therapy or assess therapeutic response.