Figure 2. An OBO-Edit ‘Ontology Tree Editor’ view demonstrating the improved Gene Ontology representing ‘kidney development’ after a focused expansion.

The Gene Ontology representing kidney development was enriched after a focused expansion with an additional 522 new terms, and as an example (using the Gene Ontology file from March 19^th 2012) the expanded node of the ‘pronephros development’ term shows it’s immediate child terms. The [+] icon beside each term denotes that there are further child terms that can be viewed; the [−] icon denotes no further child terms; (P) denotes a part_of relationship; (I) denotes an is_a relationship; (R) denotes a regulates relationship.