8971
In addition , and in support of a mediating role of STATs in the activation of the p21 promoter , overexpression of Stat3 potentiated the cytokine effect on the p21 promoter ; whereas a dominant negative Stat3 , or a mutation of the STAT response element on the promoter , significantly reduced the cytokine effect .
 STATs, p21 promoter, Stat3, p21 promoter, dominant negative Stat3, STAT response element
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 STATs, p21 promoter, Stat3, p21 promoter, dominant negative Stat3, STAT response element