The Institute for Research in Biomedicine (IRB) started its activities in spring 2000, based on joint agreements with the Universities of Bern and Zurich. Prof. A. Lanzavecchia, the scientific director, is a world-renowned immunologist and has a secondary appointment with the University of Siena (IT). The institute hosts nine world leading research groups studying different aspects of molecular and cellular immunology. Providing extensive technical and logistic support, the institute offers optimal conditions for high-level research. This environment is promoting interaction and collaboration among the researchers, which are active in different areas of biology. The institute provides several state-of-the-art instruments, animal models and techniques to study the responses of the immune system and in particular the mechanisms of cell migration. Recently, researchers at the IRB have produced a new mouse model that consists in transplantation of human cord blood CD34+ cells to newborn immuno-deficient mice. In addition, different mouse models are used at the IRB to dissect the parameters that affect the migration of bone marrow derived mature dendritic cells (DC) to the draining lymph nodes, and to analyze the impact of DC migration on T lymphocyte priming.