These groups can be put to good use when analysing microarray data with some sort of gene set analysis, like R limma geneSetTest(), GSEA, iGA or CatMap. Using one of these tools, you can analyze entire groups of genes at once to see whether a group is over or underexpressed in your experiment. To use these tools, however, you need a source of groups. Many people use Gene Ontology groups, and that's a great starting point, but people come up with groups of genes for many different reasons.

By tagging your groups with various terms when you upload (like categories or keywords), you will help create user-defined categories for groups on the fly.

The database was initially populated with groups based on:

• Gene Ontology (ref) - terms with > 5 genes in Homo sapiens, Mus musculus, Rattus norvegicus, Schizosaccharomyces pombe, Saccharomyces cerevisiae, Drosophila melanogaster, Mus musculus, Homo sapiens, Rattus norvegicus, Danio rerio, and Oryza sativa.
• Ensembl chromosome bands - Genes found in certain chromosome bands.
• L2L database (ref)- from published lists of microarray results.

Here's a poster about this database.

For more information on how to use this website as well as iGA and Catmap, check the help page.