tokens: In this study , therefore , the human monoblastic leukemia cell line U937 has been used as a model system to investigate the role of one of the RXRs , RXR-alpha , in monoblast differentiation .
folded_tokens: in this study , therefore , the human monoblastic leukemia cell line u937 has been used as a model system to investigate the role of one of the rxrs , rxr-alpha , in monoblast differentiation .
labels: O O O O O O O B-cell_line I-cell_line I-cell_line I-cell_line I-cell_line I-cell_line O O O O O O O O O O O O O O O B-protein_family_or_group O B-protein_molecule O O B-other_name I-other_name O