9516
Although retinoic acid ( RA ) has been known for many years to be a modulating agent that plays a role in generating both granulocytes and monocytes , the molecular mechanism underlying this role has not been defined in the monoblast lineage .
 ( cell type: monocytes, None) , ( cell type: monoblast lineage, None) , ( cell type: granulocytes, 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: monocytes, None) , ( cell type: monoblast lineage, None) , ( cell type: granulocytes, None) 