Founded in January 1st, 2005, the Institute of Molecular Systems Biology is a new Institute in the Department of Biology at the ETH Zurich. The mission of the Institute is to develop, apply and teach the emerging science of Systems Biology. We understand Systems Biology as an approach to biological research that studies biological systems and processes as dynamic, integrated networks of interacting molecules. The underlying vision is that the structure and dynamics of such networks will provide insights into the function and control of biological systems that are not apparent from studying the systems’s components. Neither, the technologies to collect the data required to analyze molecular networks, nor the theory and tools to extract functional information from the data is well developed at present. A significant part of the activities in IMSB will therefore focus on the development of new technologies for the collection and analysis of quantitative data at high throughput and their integration into models that represent the behavior of the systems studied. By its nature, systems biology is an interdisciplinary science. The IMSB strives to create a highly interactive working environment that is integrated within a network of collaborative projects. IMSB scientists are involved in SystemsX, the Swiss Initiative in Systems Biology, which includes the Center for Model Organism Proteomics (C-MOP) at the University of Zürich, the Competence Center for Systems Physiology and Metabolic Disease (CC-SPMD) at the ETH Zürich as well as the Center of Biosystems & Engineering (C-BSSE) of the ETH Zürich at Basel. The IMSB is also tightly linked to other international Systems Biology projects and institutes such as the Institute for Systems Biology (ISB) in Seattle, WA, the Yeast Systems Biology Network, and Advanced Systems Biology Courses.