The rapid accumulation of high-throughput data along with advances in network biology have been fundamental in improving our knowledge of biological systems and complex disease. The emergence of network medicine has explored disease complexity through the systematic identification of disease pathways and modules. Via the analysis of network topology and dynamics, key discoveries have been made including identification of novel disease genes and pathways, biomarkers and drug targets for disease. Network theory is making important contributions to the topological study of biological networks, such as: protein-protein interaction networks, metabolic networks, gene regulatory and signaling networks.