Comparing recipients of WT T cells with those receiving Ceacam1 2/2 T cells, we observed increased numbers of Ceacam1 2/2 donor alloactivated effector T cells in the spleen, MLN, and IEL of allo-BMT recipients ( Figure 3A) , which was associated with a concomitant decrease in the number of Ceacam1 2/2 alloactivated CD4 and CD8 T cells in the PLN and liver.