Despite recent progress, colon cancer remains the second leading cause of cancer death in the United States. Over the last several years new therapies, known as “targeted therapies”, have emerged which are offering patients the hope of improved outcomes with fewer side effects. This proposal is based on determining which patients with colon cancer would benefit from the use of drugs that block a gene known as Src. We will do a series of experiments in colon cancer cells and gene chips to define a patient group that will respond to these drugs before proceeding into a clinical trial.