Thrombopoietin (TPO) is a growth factor that is produced by liver and kidney tissue. TPO acts through the TPO receptor to promote megakaryocyte matu ion and differentiation, which leads to the production of platelets. Recombinant TPO is a non-glycosylated Protein, containing the 174 amino acids of the receptor binding domain, with a molecular weight of 18.6 kDa