A therapeutic biomarker is a biological indicator that helps determine how well a treatment is working for a specific disease. These markers can be found in blood, tissue, or other bodily fluids and are used to predict a patient's response to a particular therapy. By identifying these biomarkers, healthcare providers can tailor treatments to individual patients, improving outcomes and minimizing side effects. In the context of cancer treatment, therapeutic biomarkers can indicate which patients are likely to benefit from targeted therapies, such as immunotherapy or chemotherapy. This personalized approach enhances the effectiveness of treatments and supports the development of new drugs by identifying patient populations that may respond favorably.