506
Curiously, the TCF-1 alpha binding element was inactive in vivo when removed from its neighboring elements on the TCR alpha enhancer and positioned in one or more copies upstream of a heterologous promoter .
 DNA: TCR alpha enhancer; protein: TCF-1 alpha; protein: TCR; DNA: heterologous promoter
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:
 DNA: TCR alpha enhancer; protein: TCF-1 alpha; protein: TCR; DNA: heterologous promoter