Purity > 90% as determined by SDS-PAGE. MW: 45.6kDa. Partial: 22-194. N-terminal GST-tagged. Rattus norvegicus (Rat). Lineage-specific cytokine affecting the proliferation and maturation of megakaryocytes from their committed progenitor cells. It acts at a late stage of megakaryocyte development. It may be the major physiological regulator of circulating platelets.