tokens: As one test of this hypothesis , we compared the abilities of E1A -and E7 -expressing human fibroblastic or keratinocyte-derived human cells to be selectively killed by either unstimulated or interferon ( IFN ) -activated NK cells .
folded_tokens: as one test of this hypothesis , we compared the abilities of e1a -and e7 -expressing human fibroblastic or keratinocyte-derived human cells to be selectively killed by either unstimulated or interferon ( ifn ) -activated nk cells .
labels: O O O O O O O O O O O O B-protein_molecule O B-protein_molecule O O O O O O O O O O O O O B-cell_type O B-cell_line I-cell_line I-cell_line I-cell_line I-cell_line I-cell_line I-cell_line O