This volume presents the proceedings of the Fourth Annual Symposium on the Molecular Biology of Hemopoiesis, held in Reno, Nevada, November 1 and 2, 1988. Its focus on erythropoiesis represents an attempt to cover a rapidly expanding field, which has gone from elegant studies of erythro- poietin physiology, to molecular biology, to clinical applications and again to physiology. The rapid development has been made possible by cloning of erythropoietin gene and the availability of recombinant hormone. The regulation of heme and its derivatives has also been aided by techniques of molecular...