During the last decade there has been an explosion of knowledge about what cancer is and how it can be treated. As a result, scientists have developed new drugs known as targeted molecular therapies designed to zero in on the mechanisms that supply blood to tumors and promote their growth and division, which spares healthy tissue, causes fewer side effects, and improves quality of life. These drugs have been studied in clinical trials over a number of years and some have been approved by the FDA and are available for use.