Cord blood is alternative source of the haematopoietic stem cells (HSC) in relation to bone marrow and peripheral blood. Advantage of the cord blood (CB) is its relative accessibility as a source of HSC. HSC of CB present bigger proliferative potential than HSC of bone marrow and peripheral blood. Moreover they evoke weaker GvH reaction. The disadvantage of CB is its small amount obtain- able once for all. It can be applied to allogenic transplantation only, although, the banking of CB is becoming popular as a source of HSC for future autologous transplantation.

Achieving immunological tolerance is an important goal in the effort to reduce long-term morbidity and mortality in organ transplant recipients. The establishment of mixed chimerism through the transplantation of donor bone marrow cells is an experimental approach for tolerance induction with clinical potential. Permanent, robust donor-specific tolerance has been reliably achieved in various animals models of mixed chimerism.