14664
The multiple biological activities of tumor necrosis factor ( TNF ) are mediated by two distinct cell surface receptors of 55 kd ( TNFRp55 ) and 75 kd ( TNFRp75 ).
 ( protein: TNF, None) , ( protein: TNFRp75, None) , ( protein: cell surface receptors, None) , ( protein: 75 kd, None) , ( protein: tumor necrosis factor, None) , ( protein: 55 kd, None) , ( protein: TNFRp55, 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: TNF, None) , ( protein: TNFRp75, None) , ( protein: cell surface receptors, None) , ( protein: 75 kd, None) , ( protein: tumor necrosis factor, None) , ( protein: 55 kd, None) , ( protein: TNFRp55, None) 