For this recipe, we need the Bioconductor package called biomaRt and a working internet connection. We'll also need to know the BioMart server to connect to—there are about 40 worldwide, providing information about all sorts of things. The most widely accessed are the Ensembl databases and these are the default in these packages. You can see a list of all of the BioMarts here: http://www.biomart.org/notice.html. The code we'll develop will apply to any of these BioMarts with a little modification of table names and URLs, as appropriate.