Numbers of pathways, including superpathways, shared by the three PGDBs HumanCyc (H. sapiens), EcoCyc (E. coli), and AraCyc (A. thaliana). The numbers outside the circles represent the total number of pathways in the corresponding PGDB. The numbers inside the intersecting areas represent the number of pathways that fall into each area. For example, there are 55 pathways in common between HumanCyc and EcoCyc (20 + 35). AraCyc contains 177 total pathways: 76 that are unique to A. thaliana, and 101 that are shared with other organisms.