The NCBI folks have created another database, NCBI BioSystems, which is the aggregation of several public databases. This database connects biosystem records with literature, molecular and chemical data from the Entrez system. Biological pathways from KEGG nd BioCyc are currently included. Links to this database are included in records from NCBI Gene, HomoloGene, OMIM and the Protein Clusers databases. Get the full details on NCBI BioSystems here.