tokens: Human immunodeficiency virus type 1 ( HIV-1 ) negative factor ( Nef ) has been shown to down-regulate the transcription factors NF-kappa B and AP-1 in vitro .
folded_tokens: human immunodeficiency virus type 1 ( hiv-1 ) negative factor ( nef ) has been shown to down-regulate the transcription factors nf-kappa b and ap-1 in vitro .
labels: B-virus I-virus I-virus I-virus I-virus O B-virus O B-protein_molecule I-protein_molecule O B-protein_molecule O O O O O O O B-protein_family_or_group I-protein_family_or_group B-protein_molecule I-protein_molecule O B-protein_molecule O O O