9885
IL-2 and IL-7 were equivalent in their ability to induce tyrosine phosphorylation of STAT5A and STAT5B and to facilitate binding of these STATs to an immobilized GAS element .
 IL-7, immobilized GAS element, IL-2, STATs, STAT5B, STAT5A
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 IL-7, immobilized GAS element, IL-2, STATs, STAT5B, STAT5A