13394
We have tested this possibility directly using TAP-deficient cell lines lacking antigenic ER peptides derived from two model Ags , the human adenovirus type 5 early regions E1A and E1B .
 ( protein: Ags, None) , ( cell line: TAP-deficient cell lines, 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: Ags, None) , ( cell line: TAP-deficient cell lines, None) 