tokens: Rat spleen and peripheral blood lymphocytes express progesterone receptors whose concentration is increased greatly during the early phase of pregnancy .
folded_tokens: rat spleen and peripheral blood lymphocytes express progesterone receptors whose concentration is increased greatly during the early phase of pregnancy .
labels: B-body_part I-body_part O B-cell_type I-cell_type I-cell_type O B-protein_family_or_group I-protein_family_or_group O O O O O O O O O O B-other_name O