In particular for the present study concerning CRC, serum CEA is associated with prognosis and is an indicator of treatment effect and recurrence.[11,12] Other serum markers such as cancer antigen (CA)19-9[13] and CA242[14] have also been used for the diagnosis of GC and CRC and postoperative monitoring of therapeutic effect. The gene discussed is CEACAM5; the disease is colorectal carcinoma.