In lymphoid cell lines only , the E ( gre ) -binding protein complexes included ALF1 or HEB and E2A basic helix-loop-helix proteins .
in lymphoid cell lines only , the e ( gre ) -binding protein complexes included alf1 or heb and e2a basic helix-loop-helix proteins .
O B-cell_line I-cell_line I-cell_line O O O B-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region O O O O B-protein_molecule O B-protein_molecule O B-protein_family_or_group B-protein_family_or_group I-protein_family_or_group I-protein_family_or_group O