CEACAM5 and colorectal carcinoma: Although not every CRC case is associated with increased levels of serum tumor markers (CEA, CA19-9, and CA72-4), the patient from whom CWH22 and CLM22 organoid cell lines were derived had abnormally elevated preoperative CEA and CA19-9 levels (132 ng/mL and 729 U/mL, respectively), which significantly decreased postoperatively (47.05 ng/mL and 151.6 U/mL, respectively).