Since the discovery of protein kinase activity in 1954, the field of protein kinase drug discovery has advanced dramatically. With the ongoing clinical success of the Bcr-Abl kinase inhibitor Gleevec in the treatment of chronic myelogenous leukemia and seven additional marketed kinase inhibitor drugs, researchers have compelling evidence that kinase inhibitors can be highly efficacious in the treatment of diseases caused by aberrant activity of protein kinase. Currently more than 100 protein...