Entrez | PubMed | Nucleotide | Protein | Genome | Structure | OMIM | PMC | Journals | Books |
ELink: Checks for the existence of an external or Related Articles link from a list of one or more primary IDs; retrieves IDs and relevancy scores for links to Entrez databases or Related Articles; creates a hyperlink to the primary LinkOut provider for a specific ID and database, or lists LinkOut URLs and attributes for multiple IDs.
Base URL: http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?
URL parameters: (Note: utility parameters may be case sensitive, therefore, use lower case characters in all parameters except for WebEnv.
Database (db) databases available from EInfo
Record Identifier: Required if WebEnv is not used.
id=12345,92932,828282&id=1234
PMID (pubmed)
MIM number (omim)
GI number (nucleotide, protein)
Genome ID (genome)
Popset ID (popset)
SNP cluster ID (snp)
UniSTS ID (unists)
UniGene cluster ID (unigene)
MMDB-ID (structure)
PSSM-ID (cdd)
3D SDI (domains)
TAXID (taxonomy)
GEO ID (geo)
Date Parameters (onlyvalidfordbfrom=pubmed&cmd=neighbor)
Relative Dates: Limit items to the number of
days immediately preceding today's date.
term=medline[sb]Retrieval Mode:
term=human[organism]
term=biomol genomic[properties]
retmode=xml (default)Use your web browser's View Page Source function to display XML (default) results. Retmode=ref is only available for one ID.
retmode=ref (only used with cmd=prlinks)
To Database: ELink 'linking to' or destination database, pubmed is the default db. To retrieve links for all Entrez databases use db=all.
From Database: ELink 'linking from' or origination database, pubmed is the default db.
Web Environment: Value previously returned in XML results from ESearch and EPost and used with ELink in place of primary ID result list. Required if id is not used.
Query_key: The value used for a history search number or previously returned in XML results from ESearch or EPost. Required if id is not used.
Link Command Values: Default is neighbor.
Note:
- cmd=prlinks - List the hyperlink to the primary LinkOut provider for multiple IDs and database. Each ID is processed separately.
- cmd=prlinks&retmode=ref - Create a hyperlink to the primary LinkOut provider for a single ID and database.
- cmd=llinks - List LinkOut URLs and Attributes, except PubMed libraries, for multiple IDs and database. Each ID is processed separately.
- cmd=llinkslib - List LinkOut URLs and Attributes for multiple IDs and database. Each ID is processed separately.
- cmd=lcheck - Check for the existence (Y or N) of an external link in for multiple IDs and database.
- cmd=ncheck - Check for the existence of a neighbor link for each ID within a database, e.g., Related Articles in PubMed.
- cmd=neighbor - Display neighbors within a database.
- cmd=neighbor_history - Create history (WebEnv & query_key) for use in other EUtilities.
- cmd=acheck - Lists Entrez databases links for multiple IDs from a single database.
Holdings: List LinkOut URLs for the specified holding provider, e.g., library. Used only in conjunction with cmd=llinks or cmd=llinkslib
For example:
cmd=llinkslib&holding=medlib
Version: Include a version number to refer to the latest DTD.
For example:
version=1 retrieves the latest DTD (eLink_050511.dtd) that includes the additional elements, MenuTag, LinkInfo and IdLinkSet.
E-mail Address: If you choose to provide an email address, we will use it to contact you if there are problems with your queries or if we are changing software interfaces that might specifically affect your requests. If you choose not to include an email address we cannot provide specific help to you, but you can still sign up for utilities-announce to receive general announcements.
To retrieve IDs from PubMed for PMID 9298984
to the PubMed database:
http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=9298984&cmd=neighbor
To retrieve IDs from CoreNucleotide for GI 48819, 7140345 to Protein:
http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=nuccore&db=protein&id=48819,7140345
To retrieve PubMed related articles for PMIDs 11812492 11774222 with a
publication date from 1995 to the present:
http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=11812492,11774222&db=pubmed&mindate=1995&datetype=pdat
To retrieve MEDLINE indexed only related articles for PMID 12242737:
http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=12242737&db=pubmed&term=medline[sb]
To create a hyperlink to the first link available for PMID 10611131 in
PubMed:
http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=10611131&retmode=ref&cmd=prlinks
To list all available links in PubMed, except for libraries, for
PMIDs 12085856 and 12085853:
http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=12085856,12085853&cmd=llinks
To list Entrez database links for PubMed PMIDs 12169658 and
11748140:
http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=12169658,11748140&cmd=acheck
To check for the existence of a Related Articles link for PMIDs 0611131,
111645 and 12068369:
http://eutils.ncbi.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=10611131,111645&id=12068369&cmd=ncheck
To create history (WebEnv & query_key) for Protein GI 50806715,
50810195 neighbors from Nucleotide and Taxonomy:
http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?id=50806715&id=1698399&cmd=neighbor_history&dbFrom=protein&db=nuccore,taxonomy
To retrieve neighbors for Cancer Chromosomes ID 2662 to the link subset
related by cytogenetics:
http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=cancerchromosomes&db=cancerchromosomes&id=2662&cmd=neighbor&linkname=cancerchromosomes_cancerchromosomes_cyto