THPO and acute myeloid leukemia: c-MPL, a receptor for thrombopoietin, which is not only expressed in different maturation stages of megakaryocte, or early hematopoietic stem/progenitor cells, but also expressed in the primitive cells of AML, CML and MDS patients, promotes the cell proliferation and resistance to chemotherapy of various types of AML cases [32–35].