8386
These quantitative, if not qualitative, differences between signaling initiated by these two ligands for CD28 may contribute to functional differences (e.g. Th1 or Th2 differentiation ) in T cell responses .
 ( protein: CD28, 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: CD28, None) 