Institute of Molecular Systems Biology, ETH Zürich, CH-8093 Zürich, Switzerland. lars.kuepfer@imsb.biol.ethz.ch <lars.kuepfer@imsb.biol.ethz.ch>|Institute of Molecular Systems Biology, ETH Zürich, CH-8093 Zürich, Switzerland. lars.kuepfer@imsb.biol.ethz.ch <lars.kuepfer@imsb.biol.ethz.ch>|Institute of Molecular Systems Biology, ETH Zürich, CH-8093 Zürich, Switzerland. lars.kuepfer@imsb.biol.ethz.ch <lars.kuepfer@imsb.biol.ethz.ch>