It is one of the major cytokines that regulate granulocyte hematopoiesis in the bone marrow, similar to the erythropoietin EPO, which promotes hematopoiesis in the red lineage. It can selectively act on target lineage hematopoietic progenitor cells to promote their proliferation and differentiation, and can increase the function of granulocyte terminal differentiation cells, so it can not only increase the number of white blood cells, but also enhance the ability of white blood cells, and is used for neutropenia caused by cancer chemotherapy, etc., and promote the increase of neutrophil values after bone marrow transplantation, etc. It can also be used for bone marrow dysplasia caused by Neutrophil decline. It is a good idea to use it under the guidance of a doctor, not blindly, because improper use can easily cause fatigue of the bone marrow hematopoietic function, and once you stop using it, you will not be able to maintain normal immunity, just like using a whip to whip a horse to work, once you stop whip the horse will not be able to do the work.