Directed human Protein-Protein Interaction network with predicted controllability (DirectedPPI) was developed at Harvard Medical School at Norbert Perrimon’s lab and Drosophila RNAi Screening Center (DRSC), in collaboration with Albert-László Barabási’s lab at the Center for Complex Network Research at Northeastern University. The current version of the directedPPI database contains human directed PPI network, i.e. PPI network with predicted edge-direction (potential direction of signal flow between interacting proteins A and B is defined as A→B, B→A, or both), with node classification based on network controllability. The purpose of the database is to help researchers to access, build and navigate directed protein-protein interaction networks and analyze their controllability by offering a simple and interactive web interface.