CEACAM1 and colorectal cancer: For example, CEACAM1−/− mice injected with highly metastatic MC38 colorectal cancer cells and B16F10 melanoma cells experience a reduction in the number and size of metastatic lesions compared to the WT littermate, with tumor cell proliferation decreasing by 2-fold and tumor cell survival decreasing by 3-fold, indicating that expression of CEACAM1 is associated with tumorigenesis in colorectal cancer [90].