CEACAM5 and colon carcinoma: Extremely high CEA production of the primary colon carcinoma (M-24) cells in the recovered solution through PLGA/SK-10 filters was found in this study, whereas high expression of CSC marker and high colony-forming ability of the commercially available colon carcinoma cells (HT-29 in this study and LoVo cells in the previous study [13]) were found in the migrated cells and the cells in the recovered solution.