passages.id: split_1_test_975_passage
passages.type: progene_text
passages.text: It contains binding sites for several transcription factors , for example : (i) a well - characterized binding site for rel / NF-kappaB transcription factors in its 3'-end ( the H2TF1 or kappaB1 element ) , (ii) a second kappaB site ( the kappaB2 element ) , which is located immediately adjacent 5' to the H2TF1 element and which is recognized by p65 / relA in the human HLA system , and (iii) an AP-1 / ATF recognition sequence in the 5' end ( EnA - TRE ) .