In this study, we aimed to clarify the usefulness of CTC/CSC in the tumor drainage vein blood as a prognostic biomarker in CRC patients with Dukes' stage B and C. To detect the CTC/CSC, we utilized the real-time RT-PCR method using multiple marker genes consisting of CEA, CK19 and CK20 mRNA for the general CRC-associated marker, and CD133 mRNA for the CSC marker. The gene discussed is CEACAM5; the disease is colorectal carcinoma.