Natural Resistance Systems Against Foreign Cells, Tumors, and Microbes presents the proceedings of an international conference held at Timber Cove Inn Jenner, California on October 18-22, 1976. It deals with the resistance to microorganisms and tumors, the dual problems of basic immunology, and the clinical aspects of immune reconstitution. It focuses on the identification and characterization of host defense systems, endowed with specificity, yet non-induced, non-adaptive, and non-thymus dependent. Divided into 12 chapters, the book initially discusses natural resistance to foreign hematopoietic and leukemic grafts. It goes on, examining the critical issues in clinical bone marrow transplantation and graft-versus-host (GVH) disease as a consequence of bone marrow grafting. Chapters 5 to 8 discuss the role of macrophage, Hh genes, major histocompatibility complex, and natural killer cell systems in natural resistance to normal and malignant cells. The final chapters cover the mechanism of cell's natural resistance to intracellular bacteria, genetic resistance to leukomogenesis, and manipulations to control the allograft response and GVH disease. This book is an invaluable resource for those interested in basic immunology, immune reconstitution, natural resistance phenomena, and GHV disease.