THPO and acute myeloid leukemia: Thrombopoietin is the key regulator of PLT production by binding to its specific receptor thrombopoietin (TPO) receptor (TPO-R), on the megakaryocytic surface.9 A randomized, double-blind study with the TPO-R agonist, romiplostim, versus placebo for lower-risk MDS was stopped early because of an apparent increased risk of AML progression, which was not confirmed with long-term follow up.10,11