Hemoglobin switching in humans is accompanied by changes in the ratio of the transcription factors , GATA-1 and SP1 .
hemoglobin switching in humans is accompanied by changes in the ratio of the transcription factors , gata-1 and sp1 .
B-protein_molecule O O O O O O O O O O O O B-protein_family_or_group I-protein_family_or_group O B-protein_molecule O B-protein_molecule O