DOES GRAFT-VERSUS-HOST DISEASE ATTACK EPITHELIAL STEM-CELLS

Graft-versus-host disease (GvHD) is the opposite of graft rejection in that a transplant containing donor lymphocytes attacks the host's ski n, liver and gut, This disease can usefully also attack host tumor cel ls, There is a peculiar distribution of normal tissue targets in epith elial stem cell sites, suggesting that GVHD may be the abnormal counte rpart of a physiological growth control system, Efforts to understand how the graft-versus-tumor effect could be therapeutically separated f rom GvHD require further understanding of the mechanisms involved in G vHD.