Thrombopoietin
Thrombopoietin (TPO) is a hormone found in the human body. It is produced in and secreted from the kidneys, liver, striated muscle, and stromal cells in bone marrow. It works to stimulate the production and differentiation of megakaryocytes, the bone marrow cells that fragment into large numbers of platelets.
Though there are potentially many positive effects of a synthetic thrombopoietin, a safe form of this hormone has not been created. The first recombinant thrombopoietin developed was ineffective, so the research to create synthetic TPO continues. Potential uses include the procurement of platelets for donation, and the recovery of platelet counts after myleosuppressive chemotherapy.