10907
That the signal transduction pathways used by the cytokines IL-2 and IL-15 are identical would suggest that these cytokines have redundant roles in lymphoid development ; instead, IL-2 is the guardian of thymus-derived T-cell homeostasis , while interleukin-15 promotes extrathymic development of T and NK cells .
 ( protein: IL-2, None) , ( protein: IL-15, None) , ( protein: cytokines, None) , ( protein: interleukin-15, None) , ( protein: cytokines, None) , ( protein: IL-2, 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: IL-2, None) , ( protein: IL-15, None) , ( protein: cytokines, None) , ( protein: interleukin-15, None) , ( protein: cytokines, None) , ( protein: IL-2, None) 