The so called biomarkers are measurable parameters that are detected either by physical methods (e.g. by measuring blood pressure), or by using methods from biochemistry or molecular biology (to measure e.g. carbohydrates, enzymes or receptor molecules).
Measuring biomarkers provides valuable information on certain metabolic processes. Suitable biomarkers can be found in the blood, in tissue samples, and urine and can be proteins, DNA or metabolites.

Biomarkers in cancer therapy

Medical scientists use biomarkers as benchmarks to measure healthy and pathological processes in the body, and thus the progression of a disease or the success of a therapy.
The more specifically a biomarker is connected with a disease process, the more precise the information which can be derived from it.