Myelodysplastic syndrome is a disease in which the bone marrow fails to produce adequate levels of red and white blood cells and platelets so that patients become anemic and susceptible to infections and bleeding. Often this disorder terminates in leukema. The disease has become increasingly prevalent in the aged. In this report, AECC researcher Amit Verma describes the activation of a signal in these cells, mediated by tumor-derived growth factor-b (TGF-b),that results in suppression of the production of blood cells in the bone marrow. When this signal was blocked, blood cell production was stimulated in a mouse model of this disorder. These observations provide important clues as to how myelodysplastic syndrome might be treated in humans in the future.