The Gene Ontology is a well-known ontology for the annotation of genes/gene products in terms of the biological processes in which they participate, the particular molecular functions that they perform, and the cellular components in which they act. In particular, GO consists of 3 independent taxonomies, namely GO Biological Process, GO Molecular Function, and GO Cellular Component.  Ontology terms are associated with a GO id and a human readable GO name. Each gene product annotation should be accompanied by an evidence code, indicating the type of evidence that supports it. The three GO taxonomies are stored in the GO Database, which is publicly available.