7141
Previous studies have characterized the CD28 augmentation of TCR -mediated signaling in peripheral blood T cells through transcriptional activation of an IL-2 promoter CD28 response element ( CD28RE ), along with enhanced mRNA stability.
 protein: IL-2; protein: TCR; cell type: peripheral blood T cells; protein: CD28; DNA: CD28 response element; DNA: CD28RE; protein: CD28
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: IL-2, TCR, peripheral blood T cells, CD28, CD28 response element, CD28RE, CD28 
Answer:
 protein: IL-2; protein: TCR; cell type: peripheral blood T cells; protein: CD28; DNA: CD28 response element; DNA: CD28RE; protein: CD28