12550
This silencer is inactive in the most immature DN thymocytes , which probably use a distinct silencer mechanism to down-regulate CD4 gene expression .
 cell type: immature DN thymocytes; DNA: CD4 gene; cell type: thymocytes
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
 Entities: immature DN thymocytes, CD4 gene, thymocytes 
Answer:
 cell type: immature DN thymocytes; DNA: CD4 gene; cell type: thymocytes