Integrating ‘omic’ information: a bridge between genomics and systems biology

The availability of genome sequences for several organ-isms, including humans, and the resulting first-approxi-mation lists of genes, have allowed a transition from molecular biology to ‘modular biology’. In modular biology, biological processes of interest, or modules, are studied as complex systems of functionally interact-ing macromolecules. Functional genomic and proteo-mic (‘omic’) approaches can be helpful to accelerate the identification of the genes and gene products involved in particular modules, and to describe the functional relationships between them. However, the data emer-ging from individual omic approaches should be viewed with caution because of the occurrence of false-nega-tive and false-positive results and because single anno-tations are not sufficient for an understanding of gen