1666
Our previous data obtained from a tax transgenic mouse model revealed that tax transforms mouse fibroblasts but not thymocytes , despite comparable levels of tax expression in both tissues.
 protein: tax; protein: tax; cell type: mouse fibroblasts; cell type: thymocytes; protein: tax
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 protein: tax; protein: tax; cell type: mouse fibroblasts; cell type: thymocytes; protein: tax