7574
Interestingly, although mRNA expression of Smad6 was induced by activin A in HS-72 cells , Smad6 showed no antagonistic effect on activin A -induced growth arrest and apoptosis .
 ( protein: Smad6, None) , ( protein: Smad6, None) , ( cell line: HS-72 cells, 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: Smad6, None) , ( protein: Smad6, None) , ( cell line: HS-72 cells, None) 