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The transactivation of multiple cis elements , especially S and X2 , of the DR alpha proximal promoter in group II CID cells is CIITA dependent.
 X2, proximal promoter, multiple cis elements, group II CID cells, CIITA, DR alpha proximal promoter, S
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:
 X2, proximal promoter, multiple cis elements, group II CID cells, CIITA, DR alpha proximal promoter, S