ZEB2 and neoplasm: CTCs were comprised of heterogeneous cells including epithelial tumor cells, tumor cells undergoing EMT and tumor stem cells etc. [12, 37, 38], and circulating epithelial tumor cells had been shown to respond to therapy in the same way as the primary tumor [39], while the detection of EMT markers (LOXL3 and ZEB2) for CTCs in mCRC predicted poor survival and therapy response during treatment [40], hence CTC molecular characterization could offer the potential to better understand the biology of metastasis and resistance to established therapies [19].