Role of Biomarkers in Personalized Medicine

Abstract

A biological marker (biomarker) is simply a molecule that indicates an alteration in physiology from normal. For example, any specific molecular alteration of a cancer cell either on DNA, RNA, or protein level can be referred to as a molecular biomarker. A biomarker is defined as a characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention. The topic of biomarkers has been discussed in a book as well as a special report on this topic (Jain 2010, 2015). Biomarkers are further described in several chapter of this book. The expression of a distinct gene can enable its identification in a tissue with none of the surrounding cells expressing the specific biomarker. Impact of biomarkers on personalized medicine is shown schematically in Fig. 3.1.