The medical need for better cancer treatment is clear. In the developed world, roughly one in three people contracts cancer and around one in four of those die from the disease. The worldwide incidence of cancer is set to double from 10 to 20 million over the next two decades and the death rate will increase from 6 to 10 million. Advances in treatment with surgery, radiotherapy and chemotherapy have had a limited impact on mortality. Cures can be achieved in childhood cancers, testicular cancer and lymphoma, and improvements in survival rates have been made as a result of adjuvant drug treatment of breast and colorectal cancer. However, the majority of human cancers are difficult to treat, especially in their advanced, metastatic forms. There is thus a pressing need for new and effective forms of systemic therapy and the discovery of novel, mechanism-based agents directed against the molecular pathology of cancer offers huge potential .