TPO and acute myeloid leukemia: Systemic levels of several other cytokines have also been compared for AML patients and healthy controls [41,54], and the levels of Interleukin-3 (IL3), IL6, thrombopoietin (Tpo) tumor necrosis factor TNFα and stem cell factor (SCF, c-kit ligand) seem to be increased in patients with untreated AML [47,49,55,56,57,58].