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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 .
 DNase I, class II promoter, AIR-1 locus defect, MHC class II-negative cells
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 DNase I, class II promoter, AIR-1 locus defect, MHC class II-negative cells