The term cytokine is a generic name for the soluble molecules that mediate reactions between cells, acting via specific receptors on those cells. They are particularly important during effector stages of the immune system and the development of haematopoietic cells | The term cytokine is a generic name for the soluble molecules that mediate reactions between cells, acting via specific receptors on those cells. They are particularly important during effector stages of the immune system and the development of haematopoietic cells |