CEACAM1 and neoplasm: Inhibition of NK-mediated cytolysis also occurs by CEACAM-1 (CD66a), expressed on trophoblasts, whereas, CEACAM-1 in tumor cells diminishes expression of NKG2D receptors on NK cells, thus suppressing NK cytolysis implying another common link between cancer and pregnancy (Gray-Owen and Blumberg, 2006).