The BioCyc database collection is an encyclopedic set of more than 20,005 Pathway/Genome Databases (PGDBs) describing many sequenced genomes. The comprehensive website contains curated data from 130,000 publications and enables researchers around the world share fundamental information about biochemical pathways and genomes. BioCyc supports activities in drug discovery, agriculture, and biotechnology by enhancing the understanding of biological systems. New expanded versions are released three times per year.