Modeling network dynamics: the lac operon, a case study
  We use the lac operon in Escherichia coli as a prototype system to illustrate the current state, applicability, and limitations of modeling the dynamics of cellular networks. We integrate three different levels of description -molecular, cellular, and that of cell population- into a single model, which seems to capture many experimental aspects of the system. 
J. M. G. Vilar, C. C. Guet, and S. Leibler