tokens: BACKGROUND : Inhibition of complement in small animal models of xenotransplantation has demonstrated graft infiltration with natural killer ( NK ) cells and monocytes associated with endothelial cell ( EC ) activation .
folded_tokens: background : inhibition of complement in small animal models of xenotransplantation has demonstrated graft infiltration with natural killer ( nk ) cells and monocytes associated with endothelial cell ( ec ) activation .
labels: O O O O O O B-other_artificial_source I-other_artificial_source I-other_artificial_source O B-other_name O B-other_name I-other_name I-other_name O B-cell_type I-cell_type I-cell_type I-cell_type I-cell_type I-cell_type O O O O B-cell_type I-cell_type O B-cell_type O O O