A novel B-cell lineage-specific transcription factor present at early but not late stages of differentiation .
a novel b-cell lineage-specific transcription factor present at early but not late stages of differentiation .
O O B-protein_family_or_group I-protein_family_or_group I-protein_family_or_group I-protein_family_or_group O O O O O O O O B-protein_N/A O