9170
When the cells were exposed to increasing concentrations of tetracyclines , surface expression of the chimeric receptor was suppressed in a dose-dependent manner , and this suppression was sufficient to result in complete loss of responsiveness to the targeted Ag .
 ( protein: chimeric receptor, None) , ( protein: targeted Ag, 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: chimeric receptor, None) , ( protein: targeted Ag, None) 