Systems biology is a rapidly expanding field fuelled by the 'omics' era coupled to several new technological advances that have increased the precision of data obtainable, meaning that it is now feasible to obtain quantitative measurements from a single cell. The aim of systems biology is to understand the structure, dynamics and interactions of whole cells rather than the function of individual parts. The challenge now is to use these data in conjunction with modelling techniques to extend our knowledge of bacterial systems and to be able to experimentally verify in silico predictions.