We subsequently hypothesized that the compendium concept could be extended to human signatures representing genetic or pharmacologic perturbation. Signatures that proved to be similar might thus represent previously unrecognized connections (e.g., between two proteins operating in the same pathway, between a small molecule and its protein target, or between two small molecules of similar function but structural dissimilarity). Such a catalog of connections could thus serve as a functional look-up table of the human genome, and we termed this the Connectivity Map (Lamb et al., 2006).
