Cytokines are cellular growth factors which also provide communication between cells and their milieu. This clearly is an exciting area in modern medicine that will have significant impact on various facets of transfusion. Erythropoietin therapy stimulates red cell production while thrombopoietin seems to positively affect megakaryopoiesis and can be an added armamentarium for the thrombocytopenic patient. Using haematnopoietic growth factors, stem...