Additionally, Yoneda et al [11] found that serum CST1 detection might be valuable for the diagnosis of colorectal cancer, presented by the significantly elevated level of serum CST1 in cancer patients, with a sensitivity of 27.7% (95.0% specificity); furthermore, the combination of serum CST1 with carcinoembryonic antigen (CEA) and glycoantigen 19–9 (CA19-9) further improved the diagnostic sensitivity to 62.9% on the basis of the guaranted specificity at 90.0%. Here, CEACAM5 is linked to cancer.