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These results indicate that defective recruitment of NF-kappa B may underlie Nef 's negative transcriptional effects on the HIV-1 and interleukin 2 promoters .
 protein: Nef; protein: NF-kappa B
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 protein: Nef; protein: NF-kappa B