Computational Challenges of Systems Biology

B ioinformatics is the computing response to the molecular rev-olution in biology. This revolution has reshaped the life sci-ences and given us a deep understanding of DNA sequences,RNA synthesis, and the generation of proteins. In the processof achieving this revolution in understanding, we have accu-mulated vast amounts of data. The scale of this data, its structure, and the nature of the analytic task have merited serious attention from computer scientists and prompted work in intelligent systems, data mining, visualization, and more. It has also demanded serious efforts in large-scale data curation and developing a world-wide infrastructure to support this. Bioinformatics, the handmaiden of mol-ecular biology, poses novel computational challenges, stretches the state of the art, and opens unanticipated uses of computing concepts. In tackling these, computer scientists have the additional satisfaction of contributing to a scientific Grand Challenge. Bioinformatics is, however, only the first step in reshaping the life sciences. For further progress, we must return to the study of whole biological systems: the heart, cardiovascular system, brain, and liver—systems biology. To build an integrated physiology of whole systems, we must combine data from th