13854
Here we identify recurrent , early replicating , and AID - independent DNA lesions , termed early replication fragile sites ( ERFSs ) , by genome - wide localization of DNA repair proteins in B cells subjected to replication stress .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 None