10459
We have also shown that tyrosine phosphorylation of the STAT 4 transcription factor , which has been shown to be unique to the IL-12 signaling pathway, occurs with Flexi-12 at levels similar to those seen with rIL-12 .
 ( protein: Flexi-12, None) , ( protein: IL-12, None) , ( protein: STAT 4 transcription factor, None) , ( protein: rIL-12, None) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: RNA,cell type,protein,cell line,DNA, Arguments type: . 
Text: {0} 
Answer:
 ( protein: Flexi-12, None) , ( protein: IL-12, None) , ( protein: STAT 4 transcription factor, None) , ( protein: rIL-12, None) 