LY2157299 is a new type I receptor TGF-beta kinase inhibitor. LY-2157299 could inhibit TGF-β-mediated SMAD2 activation and hematopoietic suppression in primary hematopoietic stem cells. In vivo administration of LY-2157299 ameliorated anemia in a TGF-β overexpressing transgenic mouse model of bone marrow failure. Treatment with LY-2157199 stimulated hematopoiesis from primay MDS bone marrow specimens.