Few would have predicted at the time of development of modern DNA sequencing techniques that the human genome would be completely sequenced less than two decades later. In addition to the nucleic acid sequence repositories, such as the European Molecular Biology Laboratory (EMBL) and GenBank, established in the early 1980s for storing this newly acquired data, the exponential expansion of data generation also led to the development of specialized databases. These evolved from simple electronic storage areas into complex structures that provide their users with the tools necessary for viewing, understanding, mining and manipulating the complex mass of information generated.

Using the Internet to access related data in other repositories and making full use of these resources through cross-referencing has led to a dramatic expansion in the information available for a given organism. Starting from a gene entry, information can be found about all known genetic and molecular data relating to that gene and, potentially, links can be found to access 3D protein structures and molecular and genetic interactions, making it possible to explore the function of the gene product in a particular organism and in the wider biological realm. Soon became obvious that building small databases with cross references was only a partial answer to the problem of data integration. Data remained separated in silos using different standards and database schemas making the full integration uncomplete.

In this context, we embarked on a long project that involves the development of ontologies. The obvious rationale behind this is the potential of ontologies to unify the "language" spoken by different specialists . It should be noted here that the usage of very specific terms and, even worse, jargon often makes it more difficult to obtain a wide understanding of certain terms.

The two main areas we developed ontologies and IT tools driven by them are:

• The vector borne diseases (within the framework of VectorBase) and
• a pesticide resistance database (http://en.galanthos.gr)