We examined signaling by erythropoietin in highly purified human colony forming unit-erythroid cells , generated in vitro from CD34 ( + ) cells .
we examined signaling by erythropoietin in highly purified human colony forming unit-erythroid cells , generated in vitro from cd34 ( + ) cells .
O O O O B-protein_molecule O B-cell_type I-cell_type I-cell_type I-cell_type I-cell_type I-cell_type I-cell_type O O O O O B-cell_type I-cell_type I-cell_type I-cell_type I-cell_type O