12852
To determine whether BCL-6 mutations represent a tumor-associated phenomenon or reflect a physiologic mechanism, we screened single human tonsillar GC B cells for mutations occurring in the BCL-6 5'-noncoding region and in the Ig variable heavy chain sequences .
 ( DNA: Ig variable heavy chain sequences, None) , ( protein: BCL-6, None) , ( protein: BCL-6, None) , ( cell type: human tonsillar GC B cells, None) , ( DNA: BCL-6 5#$%#-noncoding region, None) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: RNA,cell type,protein,cell line,DNA, Arguments type: . 
Text: {0} 
Answer:
 ( DNA: Ig variable heavy chain sequences, None) , ( protein: BCL-6, None) , ( protein: BCL-6, None) , ( cell type: human tonsillar GC B cells, None) , ( DNA: BCL-6 5#$%#-noncoding region, None) 