Biomarkers matter, and here’s why. Biomarkers are biological clues like DNA, proteins, or genetic mutations that can be measured in your blood or tumor tissue. They help doctors understand what makes your cancer unique and guide decisions about the best treatments for your situation. How are they tested? Biomarker testing is done through a tissue biopsy (taking a sample from the tumor) or a liquid biopsy (a blood draw). These samples go to a lab and are analyzed for specific changes that your care team can use to personalize your treatment. Why it’s so important? Knowing your biomarker profile can help doctors: • Choose treatments most likely to work for you • Avoid treatments that may not be effective • Determine if targeted therapies or clinical trials are options • Understand how your cancer might behave over time You’re not alone — our Cancer Care program and Helpline are here to support you with information and guidance every step of the way. Call the Alliance's certified patient navigators for help navigating testing, treatment options, and next steps. Learn more at colorectalcancer.org. Biomarker content and Cancer Care support provided by @AmgenOncology.