1173
Activation of JAK3 , but not JAK1 , is critical for IL-2 -induced proliferation and STAT5 recruitment by a COOH-terminal region of the IL-2 receptor beta-chain .
 protein: IL-2; protein: JAK1; protein: JAK3; protein: STAT5; protein: IL-2 receptor beta-chain; protein: COOH-terminal region
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: IL-2; protein: JAK1; protein: JAK3; protein: STAT5; protein: IL-2 receptor beta-chain; protein: COOH-terminal region