[Inhibitory factors in hematopoiesis]

The author presents a short review of inhibitory factors which affect hemopoietic stem and progenitor cells. At present, the existence of naturally occurring inhibitory factors which take part in the control of hemopoiesis under pathological conditions in which they were detected, and probably even under physiological conditions, has been proved. Through their effects the inhibitory factors create a complex network of negative feed-back regulations. Their cooperation with stimulatory factors seems to be mechanism which ensures the balance in hemopoiesis and recovers it in the case of a disorder.