Cytokines are synthesized and secreted by immune cells and certain non-immune cells with a wide range of biological activities, and these small molecule proteins usually play a significant role in regulating human blood cell metabolism. Different cytokines have different physiological functions, and the common cytokines include the following: 1. Erythropoietin: Its main role is to promote the production of red blood cells, for example, erythropoietin can promote the proliferation and division of red blood cells in the bone marrow to produce a greater number of red blood cells. When the body is hypoxic, the concentration of erythropoietin will increase, stimulating further increase in red blood cells to compensate for the lack of oxygen; 2, colony granulocyte-stimulating factor and colony granulocyte-stimulating factor: its main role is to promote the production of granulocytes and monocytes; 3, thrombopoietin and interleukin 11: their main role is to promote the production of megakaryocytes and to mature platelets They are often used clinically in patients with various causes of thrombocytopenia; 4. Interleukin 2: Interleukin 2 plays an important regulatory role in intercellular interactions, immune regulation, hematopoiesis and inflammatory processes.