The reference query is used to retrieve scientific literature. CTD contains a subset of PubMed® articles that discuss chemicals, diseases, and genes and proteins of interest.
See also: Advanced Queries.
The name, symbol, CAS Registry Number, or MeSH accession ID (prefixed with “MESH:”) of a chemical cited in the title, abstract, or MeSH annotation of a reference, or involved in an interaction curated from a reference. Synonyms are also matched. To limit your search to official names, use the “name:” prefix.
Examples: dioxin, name:mercury, 1746-01-6, MESH:D001151
CTD's chemical vocabulary consists of a subset of the Medical Subject Headings (MeSH®), the hierarchical vocabulary from the U.S. National Library of Medicine. More…
The chemical vocabulary is hierarchical, so you may search by a narrow (e.g., “copper”) or broad term (e.g., “heavy metals”). Queries that use broad terms retrieve results matching the broad terms as well as related, more specific terms.
Enter your query term in the open field or choose a term from the hierarchical vocabulary by clicking the Select button and navigating through the tree.
CTD curates specific chemical–gene and protein interactions in vertebrates and invertebrates from the published literature. You may search exclusively references that have curated interactions by selecting a term in this field. Selecting ANY will match any interaction type, and effectively limits your query to references with curated interactions. Each interaction has a degree and type as defined below.
Degree. Each chemical–gene interaction is qualified by a degree: increases, decreases, affects, or does not affect (e.g., “Chemical X increases expression of Gene Y mRNA”). The affects degree is used when the reference does not describe a more specific degree. Interactions having the does not affect degree are excluded from our public data.
An interaction type must be selected in order to filter by degree(s). At least one degree must be checked.
Type. To select or deselect multiple interaction types, hold the Ctrl key (PC) or ⌘/Open-Apple/Command key (Mac) while clicking. Interaction types are searched in this hierarchy:
A gene or protein name, symbol, or accession ID (prefixed with “GENE:”) cited in the title, abstract, or MeSH annotation of a reference, or involved in an interaction curated from a reference. Synonyms are also matched. To limit your search to official symbols, use the “name:” prefix.
Examples: ahr, name:brca1, aryl hydrocarbon receptor, GENE:196
The cross-species gene vocabulary (symbols, names, and synonyms) in CTD is derived from the Gene database at the National Center for Biotechnology Information (NCBI), a division of the U.S. National Library of Medicine. CTD curators may add to this vocabulary as required (e.g., to represent a species-specific gene that is not curated in NCBI Gene).
Each curated chemical–gene interaction includes the form of the gene that is involved (e.g., promoter, mRNA, protein). Gene forms may be specified when searching for curated interaction data.
An interaction type must be selected in order to specify gene forms.
To select or deselect multiple gene forms, hold the Ctrl key (PC) or ⌘/Open-Apple/Command key (Mac) while clicking. Gene forms are searched in the hierarchy shown on the query form.
The name, synonym, or MeSH or OMIM accession ID (prefixed with “MESH:” or “OMIM:”) of a disease involved in a curated chemical or gene relationship. To limit your search to official names, use the “name:” prefix.
Examples: breast neoplasms, name:breast neoplasms, MESH:D001321, OMIM:612100
The common or scientific name of an organism or higher-order taxon in which a chemical–gene interaction was curated from a reference. To limit your search to official scientific names, use the “name:” prefix.
Examples: zebrafish, name:homo sapiens, felis catus, TAXON:9685
CTD's organism vocabulary consists of the Eumetazoa (vertebrates and invertebrates) component of the Taxonomy Database from NCBI, a division of the U.S. National Library of Medicine. The vocabulary is hierarchical, so you may search by a specific organism (e.g., “homo sapiens”) or a higher-order taxon (e.g., “mammalia”). A query that uses a higher-order taxon will retrieve results that match that taxon as well as the more specific taxa included within it.
Enter your query term in the open field or choose a term from the hierarchical vocabulary by clicking the Select button and navigating through the tree.
Words contained in the title or abstract of a reference. You may use Boolean operators.
Examples: estrogen & endometrial, estrogen | endometrial
The publication year or range of years for the references you seek. To specify a single year, select the same year in both the “from” and “through” fields. To specify a range of years, select different years in each field. To specify only the lower bound of a range, select a year in the “from” field and leave the “through” field blank. To specify only the upper bound of a range, select a year in the “through” field and leave the “from” field blank.
The PubMed accession identifiers for references. You may specify multiple IDs by separating them with spaces.
Example: 11748833 16882451
Check this box to include only CTD-curated references.
The number of results displayed per page. A lower number provides faster response.
Click the Search button to submit your query.
Click the Clear button to clear and reset all fields to their default values.
Reference query results are presented in a summary format, which includes citation information as well as the associated genes and cited chemicals for each matching reference. From results pages, you can access individual reference detail pages which provide information about a selected reference.
By default, results are sorted by:
The reference's complete author list, title, and bibliographic citation. Click the title to view more information about the reference.
The chemicals cited in the title, abstract, or MeSH annotations of the reference and identified by text mining or manual curation. Terms (and descendants of terms) that matched your query are highlighted. Click a chemical to view more information about it.
CTD's chemical vocabulary consists of a subset of the Medical Subject Headings (MeSH®), the hierarchical vocabulary from the U.S. National Library of Medicine. More…
Symbols of the genes cited in the title, abstract, or MeSH annotations of the reference and identified by text mining or manual curation. Click a gene to view more information about it.
Diseases cited in the reference and extracted by manual curation. Click a disease to view more information about it.
Sort these data differently by clicking a column heading.
Save these data into a comma-separated values (CSV), Excel, XML, or tab-separated values (TSV) file by clicking a Download link at the bottom of the table.