Therefore, due to the pleiotropic effects of CEACAM1, targeting Ceacam1 systemically may result in augmentation of inflammation; however, in the inflammatory intestinal diseases with dysbiosis (e.g., SR-Gut-GVHD), local blockade of Ceacam1 may prevent bacterial translocation and ameliorate the disease. Here, CEACAM1 is linked to graft versus host disease.