entrez_email            Set global variables
entrez_fetch            Download data from NCBI databases
entrez_global_query     See how many hits there are for a given term
                        across all NCBI Entrez databses
entrez_link             Get links to datasets related to a unique ID
                        from an NCBI database
entrez_post             Post IDs to Eutils for later use
entrez_search           Search the NCBI databases using EUtils
entrez_summary          Get summaries of objects in NCBI datasets from
                        a unique ID
parse_pubmed_xml        Summarise an XML record from pubmed.
rentrez                 rentrez
