Abstract: The present invention describes the application of specifically derived stress proteins in the modulation of certain specific immune responses in the human and animal body. This application under certain conditions may require the in vitro (out of body) treatment of certain tissues (including cells of all lineages) derived from the intended recipient body or specific donor body, in the case of organ or cell transplantation. The intracellular activity and the subsequent protection against mortality in a cell or tissue has been described in another U.S. patent, U.S. Pat. No. 5,348,945 entitled "Method of treatment with HSP70". The present invention differs from the aforementioned patent in that it does not describe a method for non-specific or specific protection against mortality. The invention may be employed to suppress allograft rejection and the rejection of xenografts, transplanted into human and/or animals.