The NCI-Nature Pathway Interaction Database: A cell signaling resource.

The Pathway Interaction Database (*PID*, http://pid.nci.nih.gov) is a freely available
collection of curated and peer-reviewed signaling pathways composed of human
biomolecular interactions and cellular processes. Created in a collaboration between the
U.S. National Cancer Institute and Nature Publishing Group, the database is a research
tool for cell biologists, biochemists, computational biologists and bioinformaticians.
The PID offers a range of tools to facilitate pathway exploration. Users can browse the
pre-defi ned set of pathways and also create interaction network maps centered on
a single molecule of interest or an extensive list of molecules. In addition, users can
download complete data sets in extensible markup language (XML) and Biological
Pathway Exchange (BioPAX) Level 2 formats. The database is updated every month and
supplemented by a concise editorial section that provides synopses of recent noteworthy
papers in cell signaling and specially commissioned articles on the practical uses of
other relevant online tools. Users can sign up for free email alerts or RSS feeds to receive
database updates