With the Atgam/aCD154 regimen (triangle), the recipients failed to develop chimerism (Figure 3, triangle). By adding anti-CD8 mAb to the Atgam/aCD154 regimen, 10/12 successfully developed mixed chimerism (Figure 3, open circle). With the thymo/bela regimen, all 4 recipients successfully developed chimerism in both lymphoid and myeloid lineages (red circle).