The tumour associated cell surface antigen A6H is costimulatory for human CD4+ but not CD8+ T cells .
the tumour associated cell surface antigen a6h is costimulatory for human cd4+ but not cd8+ t cells .
O B-protein_family_or_group I-protein_family_or_group I-protein_family_or_group I-protein_family_or_group I-protein_family_or_group B-protein_molecule O O O O O O O O O O O