A biomarker is any cellular, physical, chemical, or molecular change that can be noted and a normal or abnormal process in human body can be studied. The effects of treatment, the presence, progress or risk for a disease can be checked by studying any alteration in the normal amount of a biomarker. A tumor marker, like a biomarker, is a naturally occurring substance in the body. An increased quantity of a tumor marker can show the presence of a cancer. More
