tokens: However , the U937 monocytic cell line , which is fully permissive to HIV replication , is known to express only low levels of nuclear NF-kappa B .
folded_tokens: however , the u937 monocytic cell line , which is fully permissive to hiv replication , is known to express only low levels of nuclear nf-kappa b .
labels: O O O B-cell_line I-cell_line I-cell_line I-cell_line O O O O O O B-virus O O O O O O O O O O B-protein_molecule B-protein_molecule I-protein_molecule O