14666
Cells from TNFRp55-/-mutant mice lack expression of TNFRp55 but display normal numbers of high affinity TNFRp75 molecules .
 ( protein: high affinity TNFRp75 molecules, 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: high affinity TNFRp75 molecules, None) , ( protein: TNFRp55, None) 