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In erythroid cells most of the transcription activity was contained in a 150 bp promoter fragment with binding sites for transcription factors AP2 , Sp1 and the erythroid-specific GATA-1 .
 binding sites, transcription factors, 150 bp promoter, erythroid-specific GATA-1, Sp1, erythroid cells, AP2
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:
 binding sites, transcription factors, 150 bp promoter, erythroid-specific GATA-1, Sp1, erythroid cells, AP2