Modern cell biology has brought improvements in therapy for advanced malignant diseases through immunomodulation, hematopoietic stem cell transplantation, and other advanced techniques. Collected here are selected papers from the Fifth International Symposium of Keio University for Life Sciences and Medicine on Cell Therapy. All chapters include innovative basic research for clinical application: immunotherapy, cancer vaccination, molecular biology of hematopoietic stem cells, stem cell processing, and gene therapy. The book is divided into three parts: Immunotherapy for malignant diseases; Hematopoietic stem cell biology and clinical application; and International collaboration in hematopoietic stem cell transplantation. Included in the third part is information on bone marrow registries from around the world. The book thus presents up-to-date information on biological and clinical aspects of treatment, with insight into the future of cell therapy.