8995
B lymphocytes from patients with chronic lymphocytic leukemia contain signal transducer and activator of transcription (STAT) 1 and STAT3 constitutively phosphorylated on serine residues .
 ( protein: signal transducer and activator of transcription (STAT) 1, None) , ( cell type: B lymphocytes, 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: signal transducer and activator of transcription (STAT) 1, None) , ( cell type: B lymphocytes, None) , ( protein: STAT3, None) 