What is a Biomarker? A biomarker is a measurable, reproducible indicator of a biological process, the patient’s health, or the current state of disease. Unlike symptoms, biomarkers provide objective assessment tools that are used in a variety of ways in medicine.

How Are Biomarkers Used?

Biomarkers have several functions:

  • Monitoring patients’ health
  • Monitoring the state of a disease
  • Predicting the risk of disease development
  • Diagnosis of disease
  • Measuring the efficacy of treatment 
  • Acting as clinical endpoints in research


Examples of Biomarkers

  • Blood pressure is used to diagnose hypertension and monitor the patient’s health or response to medication. 
  • Prostate-specific antigen (PSA) is used to monitor prostate cancer and its response to therapy.
  • The presence of BRCA 1/2 mutations is used to identify individuals at risk for developing breast cancer.
  • HbA1C as a surrogate endpoint for clinical trials for the treatment of diabetes mellitus.

Source: FDA-NIH Biomarker Working Group. BEST (Biomarkers, EndpointS, and other Tools) Resource [Internet]. Silver Spring (MD): Food and Drug Administration (US); 2016-. Available from: Co-published by National Institutes of Health (US), Bethesda (MD).