CEA production by primary colon carcinoma (M-24) cells in recovered solution after filtration through PLGA-10/SK filters was found to be higher than that of primary colon carcinoma (M-24) cells cultured on TCP dishes (control) and showed CEA production similar to that of LoVo cells and much higher than that of HT-29 cells. This evidence concerns the gene CEACAM5 and colon carcinoma.