Hematopoiesis, or the process of blood formation, has been extensively studied at both basic and clinical levels. Human diseases such as thalassemia, immunodeficiency, and leukemia represent defects in this process. Approaches to treat these disorders have required a basic understanding of the biology of blood cells. For instance, hemapoietic stem
cell replacement or
bone marrow transplantation has been used to ameliorate disease. This volume focuses on hematopoiesis at a cellular and molecular level, and establishes the basis for clinical manipulation of hematopoietic cells for therapeutic benefit. In Part I, the cellular characteristics of progenitors and stem cells are explored. Emphasis