The research project "Immunobiology of minor Histocompatibility antigens" (mHags) comprises fundamental, clinical related and pre-clinical work. mHags are products of cellular polymorphic proteins that play an essential pathophysiological role in stem cell transplantation. The fundamental work focuses on cellular and biochemical characterization of the human mHags, the immunobiology, the immunogenetics and the cell and tissue expression of the mHags. The clinical related work is centred around the immunological reactions that are induced by mHags following stem cell transplantation (SCT) for haematological and non-haematological diseases. The pre-clinical work is concentrated on the use of mHags for immunotherapeutical protocols which can be applied in combination with SCT for the treatment of haematological and non-haematological malignancies.