tokens: The costimulatory molecule B7 . 1 provides a second signal critical for T cell activation .
folded_tokens: the costimulatory molecule b7 . 1 provides a second signal critical for t cell activation .
labels: O B-protein_molecule I-protein_molecule I-protein_molecule I-protein_molecule I-protein_molecule O O O O O O B-other_name I-other_name I-other_name O