1636
Thus, the use of DNase I allowed us, for the first time, to correlate the AIR-1 locus defect with class II promoter occupancy alterations and distinguish these alterations from the ones observed in phenotypically similar but genetically distinct MHC class II-negative cells .
 ( protein: DNase I, None) , ( DNA: class II promoter, None) , ( DNA: AIR-1 locus defect, None) , ( cell line: MHC class II-negative cells, 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: DNase I, None) , ( DNA: class II promoter, None) , ( DNA: AIR-1 locus defect, None) , ( cell line: MHC class II-negative cells, None) 