Forty-eight hours after transfection , EC were stimulated with NK cells or NK cell membrane extracts for 7 hr and activation was measured by a luciferase assay .
forty-eight hours after transfection , ec were stimulated with nk cells or nk cell membrane extracts for 7 hr and activation was measured by a luciferase assay .
O O O B-other_name O B-cell_type O O O B-cell_type I-cell_type O B-cell_type I-cell_type I-cell_type I-cell_type O O O O O O O O O B-protein_molecule O O