CEACAM-1, or carcinoembryonic antigen related cell adhesion molecule 1, CD66a, is a cell-cell adhesion molecule found on leukocytes, epithelial cells and endothelial cells. It is involved in three-dimensional tissue structure, angiogenesis, apoptosis, tumor suppression, tumor metastasis, and immune response. [https://www.ncbi.nlm.nih.gov/gene/634]