2308
LIF induced a dose-dependent increase in p24 antigen production in the chronically infected promonocytic cell line U1 .
 ( cell line: chronically infected promonocytic cell line U1, None) , ( protein: p24 antigen, None) , ( protein: LIF, 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 line: chronically infected promonocytic cell line U1, None) , ( protein: p24 antigen, None) , ( protein: LIF, None) 