Biomarker testing is a medical process that analyzes biological markers in a person's body, such as genes, proteins, or other substances. These markers can provide important information about health conditions, including the presence of diseases like cancer. By identifying specific biomarkers, doctors can tailor treatments to individual patients, improving the effectiveness of therapies. This testing is often used in oncology to determine how a patient might respond to certain medications. It can also help in diagnosis, prognosis, and monitoring the effectiveness of treatments. Overall, biomarker testing plays a crucial role in personalized medicine, enhancing patient care.