870
These qualitative differences in the response to T cell activation are reproduced not only when HIV-1 or HIV-2 enhancers are placed upstream of a heterologous promoter but also when these enhancers are switched between their respective LTR .
 DNA: LTR; DNA: heterologous promoter; DNA: enhancers; cell type: T cell
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: LTR; DNA: heterologous promoter; DNA: enhancers; cell type: T cell