Thrombopoietin
Thrombopoietin (TPO) is a lineage-specific cytokine affecting the proliferation and maturation of megakaryocytes from their committed progenitor cells. It acts at a late stage of megakaryocyte development. TPO may be the major physiological regulator of circulating platelets. Although IL-6 possesses thrombopoietin activity that stimulates the production of megakaryocytes and increases platelet counts in vivo, it does not appear to be the only factor with TPO activity.
Swiss-Prot Accession Number: P40225