CEACAM5 and colorectal cancer: In this study, a broad panel of biomarkers relevant for various features of tumor biology and treatment effects was monitored: CEA and CA 19-9 are well-established oncological biomarkers used in the follow-up care and prognosis of colorectal cancer patients [36,37] and CEA levels are observed to be strongly elevated in cancer patients suffering from liver metastases [38].