Linking publication, gene and protein data.

The computational reconstruction of biological systems, 'systems biology', is necessarily dependent on the existence of well-annotated data sets defining and describing the components of these systems, especially genes and the proteins they encode. Information about these components can be accessed either through structured bioinformatics databases, which store basic chemical and functional information abstracted from (or supplementing) the scientific literature, or through the literature itself, which is richer in content but essentially unstructured.