Extensive research into the molecular mechanisms of cancer disease has heralded a new age of targeted therapy. In malignant cells, key proteins that are crucial to tumor growth and survival are now being targeted directly with rationally designed inhibitors. Apart from monoclonal antibodies, small molecule therapeutics such as oncogenic protein kinase inhibitors are attracting a vast amount of investigational attention. This textbook, written by acknowledged experts, provides a broad overview of the small molecules currently used for the treatment of malignant diseases and discusses interesting novel compounds that are in the process of clinical development to combat cancer.