16748
Based on these results , we suggest that Rad9 plays an important role in nucleotide excision repair through mechanisms including maintaining DDB2 protein level in human cells .
 Chemical: nucleotide
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: nucleotide