CEACAM5 and neoplasm: Recently, we showed that NEO-201 mediated enhancement of NK killing against CEACAM5+/NEO-201+ human carcinoma cell lines, demonstrating that the binding between NEO-201 and the tumor variant of CEACAM5 can block the interaction between CEACAM5 on tumor cells and CEACAM1 on NK cells to reverse CEACAM1-dependent inhibition of NK cytotoxicity (39).