The NCI-Nature Pathway Interaction Database

Biomolecular interactions and cellular processes assembled into authoritative human signaling pathways. The NCI-Nature Pathway Interaction Database is publicly funded via the US government National Institutes of Health the data are free to use without restriction.


KEGG Pathways is a collection of manually drawn pathway maps representing our knowledge on the molecular interaction and reaction networks. Developed by Bioinformatics Center of Kyoto University and the Human Genome Center of the University of Tokyo.

BioCarta Pathways

BioCarta Pathways catalogs and summarizes resources providing information for over 120,000 genes from multiple species. The site is being provided by BioCarta, Inc. Information on Biocarta is not freely available. Check Terms and Conditions section in Biocarta website for use.

Gene Ontology

The Gene Ontology (GO) project is a collaborative effort to address the need for consistent descriptions of gene products in different databases. The GO consists of three ontologies: biological processes, cellular components and molecular functions in a species-independent manner.


Reactome is a free, online, open-source, curated resource of core pathways and reactions in human biology.


PROSITE consists of documentation entries describing protein domains, families and functional sites as well as associated patterns and profiles to identify them.