Entrez Gene is a system operated by the National Center for Biotechnology Information ( NCBI) metasearch engine, which allows simultaneous access to multiple databases and so wide-ranging searches. Furthermore, it offers a whole range of tools for data analysis and for specific searches.

Networked databases

  • 3D Domains: Contains protein domains from the Entrez Structure database.
  • Books: A growing collection of biomedical books that can be searched directly where.
  • Cancer Chromosomes: Is from the NCI / NCBI SKY / M- FISH & CGH, the NCI Mitelman database and the NCI Recurrent Aberrations assembled in Cancer.
  • Conserved domains: database of protein domains; Source for this information are Pfam, Smart and COG.
  • GDS: " GEO Data Sets" is a collection of records from the "Gene Expression Omnibus (GEO) repository".
  • Gene: contains genes from RefSeq genomes that are identified either by sequence position in the NCBI Map Viewer, or both.
  • GENSAT: Project, the expression of genes in the CNS of mice with in situ hybridization techniques and transgenic mice to map.
  • Genome: provides views of various genomes, complete chromosomes, sequence maps, and integrated genetic and physical maps are available.
  • GEO: serves as a public data collection of a large number of high-throughput experiments.
  • Journal:
  • OMIA: database of genes, inherited disorders and traits in animals (except mouse)
  • OMIM: catalog of human genes and genetic disorders. The database contains textual information, references, and numerous links to MEDLINE and NCBI databases.
  • Pop Set: Set of DNA sequences that have been compiled for the analysis of the evolutionary relationships of a population.
  • Protein ( consisting of SwissProt, PIR, PRF, PDB ):
  • PubChem ( - BioAssay, compounds and Substance ): Provides information about the biological activity of small molecules available.
  • PubMed ( scientific literature):
  • PubMed Central (scientific literature, free fully accessible ):
  • SNP:
  • Structure: the " molecular modeling Database " ( MMDB ) contains 3D structures of macromolecules, including proteins and polynucleotides.
  • Taxonomy: contains the names of all organisms, which are represented in the NCBI gene database by at least one nucleotide or protein sequence.
  • Uni genes: experimentales system for automatic classification of gene bank sequences into a non-redundant system of Genorientierten clusters.
  • Uni STS: Integrated marker and mapping data from different public sources.
  • HomoloGene: a system for automatic detection of homologies within eukaryotic gene sets.


Entrez summarizes all networked databases together with a friendly user interface. It selects one of not the individual databases, but subject areas where multiple databases are merged to some extent. For each of these topics there is a search box, which allows you to search only in this field and the databases they contain. To all areas on the main page can be called a short description that provides information about the summarized under this item databases and the data they contain.

Click the " Site Map " on the main page gives links to individual databases and Entrez tools.

Quality of the results

The quality of results depends heavily on the used database and thus of the requested information itself. Searches in PubMed Central or OMIM are usually of high quality, because the information is always, in the case of OMIM here is a paper even a book based. Also search queries according to nucleotide or polypeptide sequences are very good in general, since they are based on data from BLAST, which is also operated by the NCBI. These entries are almost always cross references to the PubMed papers designed in which the results were published, and contain so good verifiable.