A stand-alone application for classifying protein sequences and investigating their evolutionary relationships. CDTree can import, analyze and update existing Conserved Domain (CDD) records and hierarchies, and also allows users to create their own.

The CCRIS database contains chemical records with carcinogenicity, mutagenicity, tumor promotion, and tumor inhibition test results. It was developed by the National Cancer Institute (NCI). Data are derived from studies cited in primary journals, current awareness tools, NCI reports, and other sources. Test results have been reviewed by experts in carcinogenesis and mutagenesis. CCRIS provides historical information from the years 1985 - 2011. It is no longer updated.

Enables first responders and other healthcare providers and planners to plan for, respond to, recover from, and mitigate the effects of mass-casualty incidents involving accidental or terrorist chemical releases.

ChemIDplus is no longer updated. These are the final files from February 22, 2023. All ChemIDplus data have been incorporated into PubChem.

ChemIDplus was a dictionary of over 400,000 chemicals (names, synonyms, and structures). ChemIDplus includes links to NLM and other databases and resources, including links to federal, state and international agencies. NLM makes a subset of ChemIDplus data available for download. The ChemIDplus Subset does not include the structure or the toxicity data available from the NLM web versions of the database. The ChemIDplus Subset is updated monthly.

Citing Medicine provides assistance to authors in compiling lists of references for their publications, to editors in revising such lists, to publishers in setting reference standards for their authors and editors, and to librarians and others in formatting bibliographic citations.

The Clinical Questions Collection is a repository of questions that have been collected between 1991 – 2003 from healthcare providers in clinical settings across the country. The questions have been submitted by investigators who wish to share their data with other researchers. This dataset is no-longer updated with new content. The collection is used in developing approaches to clinical and consumer-health question answering, as well as researching information needs of clinicians and the language they use to express their information needs. All files are formatted in XML.

Clinical Table Search Service (formerly "lforms-service") is a web service which software programs can use for querying clinical data tables. The API for each table is designed to work with our form field autocompletion package, but can be used by other programs as well. The tables may also be accessed through FHIR APIs. The FAQ page (https://clinicaltables.nlm.nih.gov/faq.html) has further details on terms of service, etc

Provides patients, family members, health care professionals, and members of the public easy access to information on clinical trials for a wide range of diseases and conditions. Technical documentation at https://clinicaltrials.gov/ct2/manage-recs/resources

ClinVar aggregates information about genomic variation and its relationship to human health.

A stand-alone application for viewing 3-dimensional structures from NCBI Entrez retrieval service. Runs on Windows, Macintosh, and UNIX and can be configured to receive data from most popular Web browsers.