EPCAM and cancer: In this study, we demonstrated the feasibility of an EPCAM-based approach for detection and isolation of DTCs.9 We utilized the cell surface marker EPCAM because it obviated the need for harsh permeabilization (required to access cytoplasmic CK antigens), a procedure that could potentially affect nucleic acid stability.46 In addition, EPCAM-based cell capture has been used extensively for CTCs,47 and so by isolating DTCs with a parallel approach we could directly compare cancer cells from these two compartments.