4257
This was unambiguously demonstrated by the fact that plasmacytoma x B cell hybrids carrying an AIR-1 locus derived from CIITA -expressing cells do not express CIITA -specific transcripts .
 ( RNA: CIITA -specific transcripts, None) , ( DNA: AIR-1 locus, None) , ( cell line: CIITA -expressing cells, None) , ( cell line: plasmacytoma x B cell hybrids, None) , ( protein: CIITA, None) , ( protein: CIITA, 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:
 ( RNA: CIITA -specific transcripts, None) , ( DNA: AIR-1 locus, None) , ( cell line: CIITA -expressing cells, None) , ( cell line: plasmacytoma x B cell hybrids, None) , ( protein: CIITA, None) , ( protein: CIITA, None) 