The Gene Ontology (GO)  provides a controlled vocabulary to describe attributes of gene products. GO contains three ontologies that describe the molecular functions, biological processes, and cellular components of proteins.
Statistics can now be found in the footers of each table in the GREAT web output.
The human and mouse ontology data was downloaded and built between Oct 14, 2011 and Feb 18, 2012.
The zebrafish ontology was downloaded Jan 3, 2011.
GREAT v1.8 Gene Ontology statistics are available here.
GREAT v1.2 Gene Ontology statistics are available here.
Ashburner M. et al. Gene ontology: tool for the unification of biology. The Gene Ontology Consortium. Nat Genet. 25(1):25-29 (2000).