The Biomarker is “a biological molecule contained in blood, other body fluids, or tissues, a sign of a normal or abnormal process, or of a disorder or disease," like cancer as described by the National Cancer Institute (NCI). Usually biomarkers differentiate the healthy person from the patient with disease. The modifications may be caused by many factors, such as germ or somatic mutations, transcriptional changes, and post-translational changes. The spectrum of biomarkers is vast, including proteins (for instance, an enzyme or receptor), nucleic acids (e.g. micro-RNA or other non-encoding ARNs), antibodies and peptides, etc. A biomarker may also be a series of changes such as gene expression, proteomic signatures and metabolomics. Biomarker can be found in the bloodstream or excretions (stool, urine, sputum or nipple discharge) (wholly blood, serum, or plasma).