A factor known to bind to endogenous Ig heavy chain enhancer only in lymphocytes is a ubiquitously active transcription factor .
a factor known to bind to endogenous ig heavy chain enhancer only in lymphocytes is a ubiquitously active transcription factor .
O O O O O O B-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region O O B-cell_type O O B-protein_family_or_group I-protein_family_or_group I-protein_family_or_group I-protein_family_or_group O