The costimulatory molecule CD28 has a restricted tissue distribution and is expressed on T cells and some plasmacytoma cells .
the costimulatory molecule cd28 has a restricted tissue distribution and is expressed on t cells and some plasmacytoma cells .
O B-protein_family_or_group I-protein_family_or_group B-protein_molecule O O B-other_name I-other_name I-other_name O O O O B-cell_type I-cell_type O O B-cell_type I-cell_type O