can be used to elucidate the underlying cellular mechanisms associated with the cancerous condition. This is also called term enrichment or term overrepresentation, as we are testing whether a GO term is statistically enriched for the given set of genes. Methods There are a variety of methods for performing a term enrichment using GO. Methods may vary according to the type of statistical test applied, the most common being a Fisher's exact test / hypergeometric test. Some methods make use of Bayesian statistics. There is also variability in the type of correction applied for Multiple comparisons, the most common being Bonferroni correction. Methods also vary in their input – some take unranked gene sets, others ranked gene sets, with more sophisticated methods allowing each gene to be associated with a magnitude (e.g. expression level), avoiding arbitrary cutoffs. Tools MOET: a web-based gene set enrichment tool at the Rat Genome Database for multiontology and multispecies analyses PlantRegMap: GO annotation for 165 species and GO term enrichment analysis PLAZA Workbench: GO, InterPro and MapMan enrichment analysis for different plant species. The Gene Ontology Consortium (GOC) provides a Term Enrichment tool. Term Enrichment FunRich is a Windows-based free standalone functional enrichment analysis tool. Blast2GO, is a platform-independent desktop application to perform functional enrichment analysis as well as functional annotation of novel sequence data. References Bioinformatics Ontology (information science)