is not a criticism, but rather a description of the challenges in the field. It is difficult to match evolutionarily related proteins in distantly related species. While homologous DNA sequences can be found relatively easily, it is much more difficult to predict homologous interactions ("interologs") because the homologs of two interacting proteins do not need to interact. For instance, even within a proteome two proteins may interact but their paralogs may not. Each protein–protein interactome may represent only a partial sample of potential interactions, even when a supposedly definitive version is published in a scientific journal. Additional factors may have roles in protein interactions that have yet to be incorporated in interactomes. The binding strength of the various protein interactors, microenvironmental factors, sensitivity to various procedures, and the physiological state of the cell all impact protein–protein interactions, yet are usually not accounted for in interactome studies. See also Bioinformatics, Omics, Proteomics, Genomics Biological networks BioPlex Connectome Glossary of graph theory Human interactome Interaction network List of omics topics in biology Mathematical biology Metabolic network Metabolic network modelling Metabolic pathway Network medicine Protein–protein interactions Systems biology Chemoproteomics References Further reading External links Interactome web servers Protinfo PPC predicts the atomic 3D structure of protein protein complexes. IBIS (server) reports, predicts and integrates multiple types of conserved interactions for proteins. Interactome visualization tools GPS-Prot Web-based data visualization for protein interactions PINV - Protein Interaction Network Visualizer Interactome databases BioGRID database mentha the interactome browser IntAct: The Molecular Interaction Database Interactome.org — a dedicated interactome web site. Bioinformatics Molecular biology Systems biology Protein complexes