4440
STAT1 alpha activation by IL-12 correlated with increased phosphorylation of serine , but not tyrosine .
 ( protein: STAT1 alpha, None) , ( protein: IL-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: STAT1 alpha, None) , ( protein: IL-12, None) 