5847
In conclusion, we show that CD3 ligation by mAb and SE triggers a rapid, PP1 -sensitive tyrosine and serine phosphorylation of Stat3 in human CD4+ T cells .
 ( protein: PP1, None) , ( protein: CD3, None) , ( cell type: T cells, None) , ( protein: mAb, None) , ( cell type: human CD4+ T cells, None) , ( protein: Stat3, 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: PP1, None) , ( protein: CD3, None) , ( cell type: T cells, None) , ( protein: mAb, None) , ( cell type: human CD4+ T cells, None) , ( protein: Stat3, None) 