canSAR integrates data from leading medicinal chemistry databases such as ChEMBL (28) and BindingDB (29). The latest version of canSAR contains data for >2 million compounds from these databases. However, there is a large amount of data that would be useful to the wider drug discovery and cancer research communities that are not covered by these outstanding resources. We now capture an increasing number of clinical candidates, research compounds and chemical probes.