In KEGG, disease and drug information is being organized in more computable forms, especially for the analysis of molecular networks. As shown in Table 2, the disease/drug resource, called KEGG MEDICUS, consists of each of the KEGG DISEASE and KEGG DRUG databases, a specific category of the KEGG PATHWAY database and a specific category of the KEGG BRITE database. Disease information is computerized in two forms: pathway maps and gene/molecule lists. The Human Diseases category of the KEGG PATHWAY database contains about 40 pathway maps for cancers, immune disorders, neurodegenerative diseases, circulatory diseases, metabolic disorders and infectious diseases. When the detail of the molecular network is not known but disease genes are identified, we use the gene/molecule list representation and create a KEGG DISEASE entry. The entry contains a list of known disease genes and other relevant molecules including environmental factors, diagnostic markers and therapeutic drugs. The list simply defines the membership to the underlying molecular system, but is still useful for computational analysis. Table 2.KEGG MEDICUS for disease and drug informationKEGG DISEASEKEGG DRUGURLhttp://www.genome.jp/kegg/disease/http://www.genome.jp/kegg/drug/DatabaseGene/molecule lists consisting of disease genes, environmental
