Nucleic Acids Research, 2012, Vol. 40, Database issue D953 Figure 5. A screenshot of an annotated interaction network for ABL1. Each node is a protein coloured by the presence/absence of certain types of data. Each protein is annotated with chemical and biological information as indicated by the activation of the trafﬁc lights. From the left, these trafﬁc lights are green if the following data is positively available: chemical screening data (informs user of previous screening efforts against target), good afﬁnity chemical screening data (tool compounds available), drug target status (green of target is the target of an approved pharmaceutical), enzyme status (green if the protein is an enzyme, as enzymes form 50% of successful drug targets (38) and enzymatic activity is useful for assay development during target validation), structural characterization, RNAi data and structure-based and ligand-based druggability. The colour of the node is then determined from the number of different annotation types available. interaction network of biological relevance. canSAR provides chemical and biological annotation of protein interaction networks, allowing rapid identiﬁcation of highly characterized or druggable points on the network (Figure 5). This is achieved by mapping a summary of the annotation within canSAR onto each node in the network, thus highlighting druggable and chemically and genetical- ly screened targets. Moreover, through the integration in canSAR, the user can instantly access chemical screening data, launched drugs, structural annotation and other fea- tures of the protein at the click of a button directly from the interaction network. A further utility for this feature is the ability to identify alternative intervention points for an undruggable target. This annotated network can be obtained via a target synopsis, or through a batch search in the chemogenomic annotation tool. Using this network, a user is able to identify whether any closely interacting proteins are predicted as druggable by both structural and ligand-based techniques. Users are able to expand and remove individual nodes to manipulate the network, and then inspect all chemical and screening data for the entire network. Identify published 3D binding modes for a compound Compounds in canSAR can be retrieved by performing keyword or chemical structure searches; alternatively they can be obtained via their activity through a biological