The future: putting Humpty-Dumpty together again.

Successful biological analysis requires that we understand the functional interactions between key components of cells, organs and systems, and how these interactions change in disease. This information resides neither in the genome nor in the individual proteins that genes encode. It lies at the level of protein interactions within the context of sub-cellular, cellular, tissue, organ and system structures. There is therefore no alternative to copying Nature and computing these interactions to determine the logic of healthy and diseased states. The rapid growth in biological databases, models of cells, tissues and organs, and the development of powerful computing hardware and algorithms have made it possible to explore functionality in a quantitative manner all the way from the level of genes to the physiological function of whole organs and regulatory systems. Systems biology of the 21st century is set to become highly quantitative, and therefore one of the most computer-intensive disciplines.