13790
Activation of Janus tyrosine kinases ( Jak ) and Signal transducers and activators of transcription ( Stat ) after ligation of major histocompatibility complex class I ( MHC-I ) was explored in Jurkat T cells .
 ( protein: tyrosine kinases, None) , ( protein: Janus tyrosine kinases, None) , ( protein: Signal transducers and activators of transcription, None) , ( cell line: Jurkat T cells, None) , ( protein: major histocompatibility complex class I, None) , ( protein: Stat, None) , ( protein: MHC-I, None) , ( protein: Jak, 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: tyrosine kinases, None) , ( protein: Janus tyrosine kinases, None) , ( protein: Signal transducers and activators of transcription, None) , ( cell line: Jurkat T cells, None) , ( protein: major histocompatibility complex class I, None) , ( protein: Stat, None) , ( protein: MHC-I, None) , ( protein: Jak, None) 