<unk>  (;<unk> O), also known as<unk> , haematopoietin, or haemopoietin, is a glycoprotein cytokine secreted mainly by the kidneys in response to cellular hypoxia; it stimulates red blood cell production (erythropoiesis) in the bone marrow. Low levels of<unk> O (around 10 mU/mL) are constantly secreted in sufficient quantities to compensate for normal red blood cell turnover. Common causes of cellular hypoxia resulting in elevated levels of<unk> O (up to 10 000 mU/mL) include any anemia, and hypoxemia due to chronic lung disease.<unk>  is produced by interstitial fibroblasts in the kidney in close association with the peritubular capillary and proximal convoluted tubule. It is also produced in perisinusoidal cells in the liver. Liver production predominates in the fetal and perinatal period; renal production predominates in adulthood. It is homologous with thrombopoietin. Exogenous<unk> , recombinant human<unk>  (rhEPO), is produced by recombinant DNA technology in cell culture and are collectively called erythropoiesis-stimulating agents (ESA): two examples are<unk> oetin alfa and<unk> oetin beta. ESAs are used in the treatment of anemia in chronic kidney disease, anemia in myelodysplasia, and in anemia from cancer chemotherapy. Risks of therapy include death, myocardial infarction, stroke, venous thromboembolism, and tumor recurrence. Risk increases when<unk> O treatment raises hemoglobin levels over 11 g/dL to 12 g/dL: this is to be avoided. rhEPO has been used illicitly as a performance-enhancing drug. It can often be detected in blood, due to slight differences from the endogenous protein; for example, in features of posttranslational modification.
Erythropoietin
Granulocyte colony-stimulating factor
Thyroglobulin
Granulocyte-macrophage colony-stimulating factor
Hemopoietic growth factor
Growth hormone
Parathyroid hormone
Colony-stimulating factor