A prognostic biomarker is a biological indicator that helps predict the likely course or outcome of a disease, particularly in conditions like cancer. These biomarkers can be found in blood, tissue, or other bodily fluids and provide valuable information about how aggressive a disease may be or how well a patient might respond to treatment. By analyzing prognostic biomarkers, healthcare providers can make more informed decisions regarding patient management and treatment plans. This can lead to personalized medicine, where therapies are tailored to the individual based on their specific biomarkers, improving overall patient outcomes and quality of life.