Cells are the fundamental building blocks of living systems. They carry out essential life processes: sensing of the environment, active movement, metabolism of food and reproduction. Due to the dazzling complexity of the biochemical networks involved in these functions our knowledge about how cells work is still very limited. In this cluster we use methods and models from physics to discover the mechanisms that regulate the behavior of cells. We apply and develop state-of-the art super-resolution imaging, micro-fabrication and molecular biology techniques to study a wide range of topics, including the dynamics of single biomolecules in the cell, the regulatory networks governing stem cell differentiation and the movement of cells in response to external cues. The ultimate goal of our program is to contribute to the mechanistic understanding of human diseases.