tokens: PU . 1 is expressed at high levels in B cells , mast cells , megakaryocytes , macrophages , neutrophils , and immature erythroid cells and at lower levels in mature erythrocytes .
folded_tokens: pu . 1 is expressed at high levels in b cells , mast cells , megakaryocytes , macrophages , neutrophils , and immature erythroid cells and at lower levels in mature erythrocytes .
labels: B-protein_molecule I-protein_molecule I-protein_molecule O O O O O O B-cell_type I-cell_type O B-cell_type I-cell_type O B-cell_type O B-cell_type O B-cell_type O O B-cell_type I-cell_type I-cell_type O O O O O B-cell_type I-cell_type O