9241
The natural dominant negative HLH factor Id3 , which blocks transcriptional activity of a number of known bHLH factors , was expressed in CD34+ progenitor cells by retrovirus-mediated gene transfer.
 protein: bHLH factors; protein: Id3; cell type: CD34+ progenitor cells; protein: dominant negative HLH factor
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: bHLH factors, Id3, CD34+ progenitor cells, dominant negative HLH factor 
Answer:
 protein: bHLH factors; protein: Id3; cell type: CD34+ progenitor cells; protein: dominant negative HLH factor