This book provides an overview of the available evidence surrounding immunotherapy in gastrointestinal cancers, and discusses its future place in clinical practice. Immunotherapy has celebrated some astonishing therapeutic successes in a variety of cancer types and is becoming increasingly relevant in daily clinical practice. Currently, the predominant class of immunotherapeutic drugs is the so-called checkpoint inhibitors, which disengage the physiological brakes on the immune system, enabling a more effective anti-cancer immune response. Malignancies of the gastrointestinal tract, which account for the majority of cancer cases worldwide, are a major cause of morbidity and mortality, creating an urgent need for more effective therapies. A large number of clinical trials have evaluated the efficacy of cancer immunotherapy in gastrointestinal malignancies and demonstrated its potential in certain subsets of patients. This book will appeal to a wide readership, including oncologists, health care professionals in general and biomedical scientists.