7299
Together, our data show that bcl-xL is essential for normal erythroid development and suggest a regulatory hierarchy in which bcl-xL is a critical downstream effector of GATA-1 and erythropoietin -mediated signals .
 ( protein: erythropoietin, None) , ( protein: bcl-xL, None) , ( protein: GATA-1, None) , ( protein: bcl-xL, 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: erythropoietin, None) , ( protein: bcl-xL, None) , ( protein: GATA-1, None) , ( protein: bcl-xL, None) 