ClearCell FX and Polaris workflow for marker-free enrichment of CTCs. The schematic diagram depicts the key steps involved in the capture and isolation of CTCs using a two-pronged system. ClearCell FX uses a spiral chip to size-sort CTCs. Polaris performs single-cell capture and cDNA synthesis of potential CTCs after depletion of cells that are PTPRC/CD31-positive. Finally, cDNA thus received is subjected to library preparation and RNA sequencing.