The control of blood cell production

It is now more than twenty years since the discovery of the clonal growth of blood cells in vitro, but the last two years have seen remarkable developments which allow scientists to return to the study of the physiology of blood cell production. The concentrated blend of cell biology, protein chemistry, genetic engineering and animal studies presented at a recent meeting∗ highlighted the complexity of the control signals for blood cell production. Nevertheless, the animal studies indicated an immediate and powerful role for the blood cell growth factors during chemotherapy and infection control.