Table 2. Differences of organ and bone marrow transplantation.

Feature marrow	Organ	Bone
Host cytoablation	No	Yes*
HLA matching	Not essential	Critical
Principal complication	Rejection	GVHD
Immunosuppression-free	Rare	Common
Term for engraftment	Acceptance	Tolerance

^*Three decades later, it was realized that this therapeutic step accounted for all of the other major differences between the two kinds of transplantation