262
However, unlike another tumor suppressor protein , p53 , Rb did not have any significant effect on basal levels of transcription , suggesting that Rb specifically interacts with IE2 rather than other cellular factors involved in the general transcription machinery .
 ( protein: p53, None) , ( protein: Rb, None) , ( protein: Rb, None) , ( protein: cellular factors, None) , ( protein: IE2, None) , ( protein: tumor suppressor protein, 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: p53, None) , ( protein: Rb, None) , ( protein: Rb, None) , ( protein: cellular factors, None) , ( protein: IE2, None) , ( protein: tumor suppressor protein, None) 