Currently, the CellSearch® system (Menarini Silicon Biosystems, Inc., Huntingdon Valley, PA, US), which utilizes ferrofluids loaded with an epithelial cell adhesion molecule (EpCAM) antibody to capture CTCs [13], is the only system approved by the US Food and Drug Administration (FDA) system for clinical use in metastatic breast, prostate, and colorectal cancers [14]. This evidence concerns the gene EPCAM and colorectal cancer.