Fig. 1

The origins of biomarkers for liquid biopsy. Molecular alterations of circulating materials, such as cell-free DNA, circulating tumor cells, exosomes, and circulating nucleosomes and RNA, can be used as biomarkers for cancer diagnosis and prognosis. Genetic biomarkers can be identified via mutational profiling of nucleic acids extracted from circulating tumor cells. Epigenetic biomarkers can be obtained via methylation profiling and nucleosome foot printing of cell-free DNA, circulating tumor cells, and circulating nucleosomes and RNA