9921
Analysis of Tax mutants showed that two mutants, IEXC29S and IEXL320G , were unable to significantly transactivate the c-sis/PDGF-B promoter .
 ( protein: IEXL320G, None) , ( protein: Tax, None) , ( protein: c-sis/PDGF-B, None) , ( DNA: c-sis/PDGF-B promoter, None) , ( protein: Tax mutants, None) , ( protein: IEXC29S, 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: IEXL320G, None) , ( protein: Tax, None) , ( protein: c-sis/PDGF-B, None) , ( DNA: c-sis/PDGF-B promoter, None) , ( protein: Tax mutants, None) , ( protein: IEXC29S, None) 