[Regulation of erythropoiesis: recent progress and current uncertainties]

Rapid progress has occurred recently in characterizing the molecular structure of the glycoproteins controlling the growth, maturation and functional activities of hematopoietic cells. Several of these factors have been purified and cDNAs have been cloned, providing them in sufficient quantities for study and eventual clinical use. Both availability of these molecules and in vitro colony assays have revealed a large number of effects on erythroid differentiation. But, except erythropoietin (EPO), the physiological role of these hormones and their relative contributions to normal erythropoiesis remain to be specified. This paper attempts to review the most important data on this topic in 1990.