(A) Mean (±SEM) spleen weight (expressed as the percentage of body weight) of control, W/W^v, sph/sph, and BMT recipients at the time of death. (□) +/+ control, n = 2. (▪) W/W^v control, n = 2. (▤) sph/sph control, n = 17. (▩) +/+→+/+^a, n = 9. (░) +/+→W/W^v, n = 10. (▧)sph/sph→+/+^a, n = 32. ()sph/sph→W/W^v, n = 10. (B) Mean (±SEM) heart weight (expressed as the percentage of body weight) of control, W/W^v, sph/sph, and BMT recipients at the time of death. Bars are as defined for (A); numbers in each group are as in (A), except forsph/sph→+/+^a, in which n = 28.