“…Recently, microfluidic chip technology has aroused great interest due to its low sample cost, high speed, good flexibility, high-throughput performance, and suitability for integrating multiple functional units for cell manipulation. − Various types of microfluidic chips have been designed based on optical trapping, , dielectrophoresis, − inertial focusing, , magnetic tweezers, or acoustophoresis. , Although each technique has its own limitations because of the heterogeneity of tumor cells, it performs well in the enrichment of CTCs under certain conditions. Among these techniques, magnetic separation is a promising tool for CTC enrichment due to its easy manipulation, high capture efficiency, and convenient coupling with immunocytochemistry and the polymerase chain reaction assay. − …”