The miRNA Targets  ontology contains genes downregulated after microRNA overexpression. The sets were collected by Ron Shamir's group from the literature.
Statistics can now be found in the footers of each table in the GREAT web output.
All ontology data was downloaded and built between Oct 14, 2011 and Feb 18, 2012.
GREAT v1.8 miRNA Targets statistics are available here.
GREAT v1.2 miRNA Targets statistics are available here.
Linhart, C., Halperin, Y., Shamir, R. Transcription factor and microRNA motif discovery: the Amadeus platform and a compendium of metazoan target sets. Genome Res. 2008 Jul; 18(7):1180-9.