When we assessed the expression of trafficking molecules in recipients of WT vs. Ceacam1-Tg T cell allografts, we found no significant differences in levels of b 7 subunit, integrin a 4 b 7 ( Figure 5B ), or any other molecules. This is consistent with the systemic reduction in GVHD in recipients of Ceacam1-Tg T cells. Finally, we assessed trafficking molecules in irradiated WT vs. Ceacam1 2/2 recipients of identical donor allografts, and observed again that donor CD8, but not CD4 splenic T cells in Ceacam1 2/2 