Systems biology is an integrative discipline that seeks to explain the properties and behaviour of complex biological systems in terms of their components and their interactions. Molecular Systems Biology is a peer-reviewed open access journal that publishes high-quality research in the fields of systems biology, synthetic biology and systems medicine. The Editors select manuscripts based on their novelty and wide biological significance. Although the primary emphasis of the journal is on molecular components and their interactions, systems studies at the organ level may also be considered. Works describing large-scale datasets will be judged, in part, by the extent to which these datasets are integrated both with each other and with computational models, with the ultimate aim to better understand the dynamic and complex nature of living systems. Reports of new experimental methods will also be considered in the context of this policy.