Bioconductor also offers facilities for directly accessing online resources through their application programming interfaces. This can be valuable when a resource is not represented in an annotation package or when the very latest version of the data is required. The rtracklayer package accesses tables and tracks underlying the UCSC Genome Browser, and the biomaRt package supports fine-grained on-line harvesting of Ensembl, UniProt, COSMIC (Catalogue Of Somatic Mutations In Cancer) and allied resources. Many additional packages access web resources, for example, KEGGREST, PSICQUIC and Uniprot.ws.
