The National Cancer Institute (NCI) Center for Bioinformatics (NCICB) has established a Pathway Interaction Database (PID) (publicly-accessible at http:I/cmap.nci.nih.gov/PWI) as a highly structured, curated repository of molecular biology information about known biomolecular interactions. It includes interactions that compose signaling, metabolic, and regulatory pathways known or believed to be active in humans. The current data set, consisting of about 7,000 interactions, has been created by importing relevant information from KEGG (Kyoto Encyclopedia of Genes and Genomes) (mainly metabolic interactions) and BioCarta (mainly signaling interactions). The latter involved a large amount of manual effort since BioCarta provides information in the form of pathway images rather than as structured data.
