12009
These isoforms ( elf-2a and elf-2b ) contain identical RBTN-2 binding regions and DNA-binding domains .
 RBTN-2, elf-2b, DNA-binding domains, elf-2a, RBTN-2 binding regions
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:
 RBTN-2, elf-2b, DNA-binding domains, elf-2a, RBTN-2 binding regions