Allogeneic stem cell transplantation (ASCTx) represents the most commonly applied therapeutic use of stem cells from born individuals. The mortality and complication rate of ASCT is high, often preventing its use in less severe conditions than cancer. Th e aim of this project is to generate a better platform for more advanced ASCT regimens including the use of stem cells for theapy. On the basis of an animal model for ASCTx and an array of immunological, molecular and gene screening techniques we want to identify novel genes and molecules important for the acceptance of a stem cell transplant. With this system er are also testing the effect of further cellular therapy (immune cells, stem cells) on the ASCT recipient, hopefully to reveal novel mechanisms o f immune modulation preventing graft-vs-host disease, a threatening complication aftter ASCTx. We are members of an EU 6FP network (TRANSNET) where genetic information gained from the animal experiments rapidly can be compared with a large panel of genes from ASCTx transplanted patients in Europe. Hopefully this can lead to better selection criteria and treatment modalities for stem cell donors in future.