This book reviews the history of immunotherapy and the available therapies including the ones applied in Russia and described in Russian journals, which is frequently unavailable for western readers. The book offers a new standing point towards cancer therapy in general and cancer immunotherapy in particular. It gives special attention to the specific and general mechanisms the cancer cells engage in to evade the surveillance of the immune system and discloses the notion of precision immunotherapy. The term immune insufficiency and its development is discussed in detail. A unique and original inter-disciplinary viewpoint relies on authorial research and three-decade experience in using stem cell therapy for different nosologies.