The differentiation of naive T-helper ( Th ) cells into cytokine -secreting effector Th cells requires exposure to multiple signals , including exogenous cytokines .
the differentiation of naive t-helper ( th ) cells into cytokine -secreting effector th cells requires exposure to multiple signals , including exogenous cytokines .
O O O B-cell_type I-cell_type I-cell_type I-cell_type I-cell_type I-cell_type O B-protein_family_or_group O O O O O O O O O O O B-protein_family_or_group I-protein_family_or_group O