Using cancer genetics to guide the selection of anticancer drug targets

The genetic alterations that cause cancer are coming into view. Genes that are recurrently mutated in a particular form of human cancer flag the proteins (or molecular pathways) that are critical for the evolution of that malignancy. The first generation of anticancer agents prospectively guided by these principles, for which imatinib mesylate is a prototype, inhibit the biochemical activities that result from gain-of-function oncogenic mutations. Advances in somatic cell genetics and chemical biology should facilitate the development of a second generation of agents that will inhibit proteins that are selectively required for survival in the context of specific cancer-causing mutations, whether loss-of-function or gain-of-function.