EPCAM and neoplasm: Different methods have been established to isolate CTCs, which can be broadly classified as either label-dependent (a positive selection of CTCs making use of specific markers expressed by tumor cells, such as epithelial cell adhesion molecules (EpCAM), cytokeratins (CKs) and integrins) [15] or label-independent (based on physical property differences such as size and density between CTCs and surrounding blood cells) [16].