1131
After stimulation by PMA , RXR alpha expression increased in H9 and U937 cells but not in CEM cells .
 ( protein: RXR alpha, None) , ( cell line: U937 cells, None) , ( cell line: H9, None) , ( cell line: CEM 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: RXR alpha, None) , ( cell line: U937 cells, None) , ( cell line: H9, None) , ( cell line: CEM cells, None) 