4003
Three subtypes of retinoic acid receptors ( RAR ), termed RAR alpha , RAR beta , and RAR gamma , have been described.
 ( protein: RAR gamma, None) , ( protein: RAR, None) , ( protein: RAR beta, None) , ( protein: RAR alpha, None) , ( protein: retinoic acid receptors, 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: RAR gamma, None) , ( protein: RAR, None) , ( protein: RAR beta, None) , ( protein: RAR alpha, None) , ( protein: retinoic acid receptors, None) 