13441
To test whether this putative function of CD28 is mediated via a particular signaling pathway, we compared early signaling events initiated in resting T cells by the stimulatory mAb BW 828 with signals triggered by the nonstimulating CD28 mAb 9.3 .
 ( cell type: T cells, None) , ( protein: CD28, None) , ( protein: stimulatory mAb BW 828, None) , ( protein: CD28, None) , ( protein: nonstimulating CD28 mAb 9.3, 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:
 ( cell type: T cells, None) , ( protein: CD28, None) , ( protein: stimulatory mAb BW 828, None) , ( protein: CD28, None) , ( protein: nonstimulating CD28 mAb 9.3, None) 