The invention is directed to the use of cpn10 in transplantation and particularly to treatment and/or prevention of graft versus host disease. The invention provides a method of administration of cpn10 to a donor and/or recipient animal or cells, tissues or organs derived from the donor, although in a particularly advantageous form treatment of both the donor and recipient animal. The method may further include the administration to the donor and/or recipient animal at least one other immunosuppressive agent to prevent or alleviate graft versus host disease.
