6720
Furthermore, the same cell lines were resistant to cytolytic action of other cytotoxic proteins secreted by LAK cells .
 ( protein: cytotoxic proteins, None) , ( cell line: cell lines, None) , ( cell line: LAK cells, None) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: RNA,cell type,protein,cell line,DNA, Arguments type: . 
Text: {0} 
Answer:
 ( protein: cytotoxic proteins, None) , ( cell line: cell lines, None) , ( cell line: LAK cells, None) 