7192
Dex acted directly on erythroid progenitors and maintained the colony-forming capacity of the progenitor cells expanded in liquid cultures .
 ( cell type: erythroid progenitors, None) , ( cell type: progenitor cells, None) , ( cell line: liquid cultures, 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: erythroid progenitors, None) , ( cell type: progenitor cells, None) , ( cell line: liquid cultures, None) 