Tumor markers are substances, usually proteins, produced by the cancer tissue itself or sometimes by the body in response to cancer growth. Because some of these substances can be detected in body samples such as blood, urine, and tissue, these markers can be used in conjunction with other tests and procedures to help detect and diagnose certain types of cancer, predict and monitor a person’s response. detect specific treatments and recurrence. More recently, the idea of ​​what constitutes a tumor marker has expanded. New types of tests have been developed that look for changes in genetic material (DNA, RNA) rather than proteins in patient samples. Genetic changes have been found to be associated with certain cancers and can be used as tumor markers to help determine prognosis, guide targeted therapy, and / or detect cancers early. Moreover, advances in technology have led to tests that can simultaneously evaluate several genetic markers or panels of markers and provide ample information about the characteristics of a tumor. Examples of these are included in the table in this article, along with more traditional tumor markers.