1476
The promoter region ( P1 ) corresponding to the main group of transcription initiation sites is devoid of TATA and CAAT boxes but has putative binding sites for the transcription factor SP1 and is embedded in a large G + C - rich domain of a CpG island , features shared by the promoters of constitutively expressed housekeeping genes .
 GENE: transcription factor SP1
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 GENE: transcription factor SP1