Modelling the Virtual Physiological Human

Systems biology – the theme of this issue of The Biochemist – can be thought of as more a philosophy of biology than a distinct set of techniques. It arose out of, but is distinct from, the genome projects and associated initiatives. The ‘catalogues’ of genes and proteins produced in recent years have generated enormous advances, but they do not tell the whole story. Nobel Laureate Sydney Brenner said in 2001 that “I know one approach that will fail, which is to start with genes, make proteins from them and try to build things bottom-up”¹. In contrast with the reductionism of genomics, systems biology is ‘integrative’: as another Nobel Laureate, David Baltimore, writes, “it seeks to understand the integration of the pieces to form biological systems”². Thus a typical systems biology study will involve both experimental analysis and computational modelling of a biological system at a number of levels: theoretically, at least, including the molecule, the pathway, the organelle, the cell, the tissue or organ, and the organism.