6722
This finding may provide a tool to improve current protocols of immunotherapy and insights to how tumor cells are or are not killed by LAK cells .
 ( cell type: tumor cells, 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:
 ( cell type: tumor cells, None) , ( cell line: LAK cells, None) 