6869
To better understand signals controlling proliferation and viability, erythroid cells that resist apoptosis in the absence of EPO were subcloned and characterized ( HCD57-SREI cells ).
 ( protein: EPO, None) , ( cell line: HCD57-SREI 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: EPO, None) , ( cell line: HCD57-SREI cells, None) 