tokens: A cDNA clone , B4-2 , was isolated from a natural killer ( NK ) minus T cell subtractive library .
folded_tokens: a cdna clone , b4-2 , was isolated from a natural killer ( nk ) minus t cell subtractive library .
labels: O B-DNA_family_or_group I-DNA_family_or_group O B-DNA_molecule O O O O O B-DNA_family_or_group I-DNA_family_or_group I-DNA_family_or_group I-DNA_family_or_group I-DNA_family_or_group I-DNA_family_or_group I-DNA_family_or_group I-DNA_family_or_group I-DNA_family_or_group I-DNA_family_or_group O