EPCAM and neoplasm: In the following CTC identification step, multiple markers, such as the positive tumor-specific markers (e.g., commonly EpCAM or CKs), the cell nucleus markers (e.g., DAPI or Hoechst), and the negative blood cell-specific markers (e.g., CD45 of WBCs) [14,15] are utilized to distinguish the target CTCs from the surrounding blood cells.