610
These results indicate that an internal short element located at the very 5 ' terminal of L1 sequence and the nuclear factor binding to the element play a crucial role in the transcription of human L1 .
 L1 sequence, human L1
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 L1 sequence, human L1