reviews the molecular aspects that characterize the spectrum of neoplastic conditions that affect the gastrointestinal tract, providing the reader with current up-to-date knowledge. For each disease entity chapters provide reviews on: • the molecular basis of the individual disease • molecular testing approaches currently available or in development for diagnosis or for gene target characterization for selective targeted therapies • recommended guidelines for clinical application of molecular tests are included whenever available • molecular testing for hereditary predisposition or disease risk • animal models and cell culture models of disease