1701
Cells expressing the E1A oncoprotein were selectively killed by unstimulated NK cells , while the same parental cells but expressing the HPV type 16 ( HPV-16 ) or HPV-18 E7 oncoprotein were resistant to NK cell lysis .
 cell line: unstimulated NK cells; protein: E7; protein: E1A; cell type: parental cells; protein: E7 oncoprotein; protein: E1A oncoprotein
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 cell line: unstimulated NK cells; protein: E7; protein: E1A; cell type: parental cells; protein: E7 oncoprotein; protein: E1A oncoprotein